After reading countless other reviews, walk-throughs, and suggestions, it has become evident to me that the most popular advice for beating many of the boss navis in the storyline is to take into consideration their elemental-based advantages and disadvantages. While this is actually highly effective, it is also not always MANDATORY or even necessary. It IS still possible to beat all of them without having to rely on elemental advantages, especially for those who are not entirely based on a certain element like beastman or drillman, among a few others. Granted that Flashman, Bubbleman, Desertman, Plantman, and Flamman all use specific elements, there are other ways to beat them easily without necessarily using this to your advantage. I say this because many people, including myself, sometimes wish to specialize in only one type of element, or even no type of element, but also because when you acquire a "style" change, your own primary elemental style must be taken into consideration against enemies unless you change to "Normal Style" before each fight. Some people may prefer not to have to spend excess time gathering element specific chips and altering their folders before each boss fight.

 So with that said, I am going to share a list of chips that I prefer to use in my primary custom folder which are helpful in almost every situation, against any boss navi or virus type, and can be considered "Nuetral" or even "flexible", meaning your navi will be adaptable to different battle situations or against specific types of viruses or bosses in accordance to the whole elemental advantage or disadvantage factor. Most of these chips that I use were actually obtained during early stages of the game, and of course, with a little luck from the chip trader machines, as well as other special methods of acquiring them or obtaining them for myself, however, none were traded between different game versions via the link cable feature.

 So here is a list of the chips that I tend to favor or use the most, and a brief explanation of how to obtain them for yourself:

 Sword (80 Dmg)

WideSwrd (80 Dmg)

LongSword (80 Dmg)

Guard (Reflects attacks)

CopyDmg - temporarily target additional enemies (If multiple on the field), that will also receive dmg from an attack that hits any other
                           non-targeted enemy

Invis - temporarily renders you invisible and immune to MOST attacks

Airshoes - allows you to walk over empty or missing panels

AreaGrab - steals the first enemy row of panels for a while - also does 10 Dmg if it hits an enemy on that row but will not steal a panel
                          that an enemy is standing on

Barr 10 - Barrier that nullifies attacks up to 10 Dmg but is destroyed if hit with stronger attacks

Barr 100 - Barrier that nullifies attacks up to 100 Dmg but is destroyed if hit with stronger attacks

Barr 200 - Barrier that nullifies attacks up to 200 Dmg but is destroyed if hit with stronger attacks

FstGuage - speeds up the custom refill guage at the top of the battle screen

AntiDmg - when hit while this is active or after it has been activated, megaman throws down a decoy doll
                     and leaps up into the air throwing three ninja stars at the enemy, or enemies if more than one
                     dealing 100 Dmg per each hit

AntiNavi - when used against friends in a linked navi battle, "Takes the enemies navi away". Not entirely sure
                  how to best explain the use of this chip on it's own to be honest since i've never been able to have
                  an actual linked battle and try it out

Muramasa - Inflicts damage to any enemy that is hit, equal to the amount of damage you have taken from full health
                  to the amount of health you have at the moment of activation. If you have lost 200 Hp it does 200 Dmg, etc, etc.

FoldrBak - When activated, it restores your entire chip folder and immediately opens the custom loadout screen for new
                     battle chip selection

AirSwrd - does up to 100 Dmg when used and also pushes all enemies to the back row of panels

FireSwrd - 130 Base Dmg - doubled on grass panels to 260 Base dmg, or against plant type enemies to 260 Dmg,
                     or if used against a plant type enemy on a grass panel, I believe it becomes (130 x 2 = 260, 260 x 2 = 520) = (130 x 4 = 520)
                     Also - I believe Dmg is halved against aqua type enemies, halved against enemies on ice panels, and reduced
                     to 1/4th damage against aqua type enemies on ice panels.

AquaSwrd - 150 Base Dmg - Believed to be doubled against earth, stone, ground, or dirt type enemies, possibly such as Desertman
                        and also possibly against electric type enemies such as Flashman, and fire type enemies such as Flamman,
                        also possibly doubled on sand panels, but halved against plant type enemies or on grass panels, and 1/4th Dmg
                        against plant type enemies on grass panels

ElecSwrd - 130 Base Dmg - doubled against water enemies or on ice panels, X4 against water enemies on ice panels, and possibly
                        1/4th Dmg against any rock/stone, ground, sand, dirt type enemies or possibly even plant type enemies or on any
                           plant or sand type panels

BambSwrd - 140 Base Dmg - doubled against electric type enemies such as Flashman, possibly half Dmg against water type enemies,
                           or enemies on ice panels, and 1/4th Dmg against water type enemies on ice panels

Salamndr - 300 Base Dmg (Uses same Dmg enhancers and reducers as FireSword or basic fire type chips)
                           "Send Fire into hole" - believed to be able to shoot a flame into an empty or missing panels on the
                              battlefield and then erupt with some flames coming out of the hole hitting the panels around it

Fountain - 240 Base Dmg (Uses same Dmg enhancers and reducers as Aquaswrd or other water type chips)
                              "Draw Water from hole" - believed to draw a fountain of water out of an empty or missing panel
                                 on the battlefield and expand out to hit panels around the hole

Bolt - 210 Base Dmg (uses same Dmg enhancers and reducers as Elecswrd or other ELectric type chips)
                              "Damages objects and area" - believed to target and hit any obstacle objects on the field
                                 such as rockcubes, rook, pawn, knight, fan, vacuum, etc as well as striking random
                                 panels on the field

GaiaBlad - 100 Base Dmg (uses same Dmg enhancers and reducers as Bambsword or other wood type chips)
                                 "Takes power from next chip" - when chosen in the chip selection screen, any chip chosen
                                 after this chip, will convert it's base dmg value into an additional Dmg boost for this chip,
                                 for every chip that has any Base Dmg value that is chosen after this chip

Now, some of these chips may seem to do only a small amount of damage on their own, but many of them can actually
   be used together to create something called a "Program Advance", which is basically just a more powerful "Combination"
 attack. Below, I will list the "Program Advances", or P.A.'s that I use in this folder:
 
 LifeSwrd - Sword, WideSwrd, LongSwrd (400 Dmg)
ElemSwrd - FireSwrd, AquaSwrd, ElecSwrd, BambSwrd - believed to do at least 100 Dmg per hit for up to four hits
                     but may also include any elemental Dmg enhancements or Reductions
Barr 500 - Barr 10, Barr 100, Barr 200 - Creates a Barrier that nullifies attacks up to 500 Dmg but may be destroyed
                     by stronger attacks
MstrStyle - Salamndr, Fountain, Bolt, Gaiablad - believed to do up to 100 Dmg per attack for up to 8 - 9 attacks,
                     may also possibly include any Elemental Dmg enhancments or reductions
BodyGrd - AntiDmg, AntiNavi, Muramasa - believed to deal up to 100 Dmg per hit for up to 9 - 12 hits of
                        raining ninja stars that seem to auto-lock or target any enemy(ies) on the field one at a time if multiple

 Now many of these chips are actually quite easy to obtain at early stages of the game with a little luck and a good bit of gathering other chips, zenny, or bugfrags. Some can actually be found in the "Mystery Data" which are the little colored floating diamonds around the cyber world, some can actually be obtained as rewards when you defeat some certain types of viruses with a high enough "Busting Level", some can obviously be purchased at different shops in the cyber world or traded at bugfrag traders in the cyberworld, some can be obtained by trading chips in the chip traders in the real world, and some can be obtained by entering winning lotto ticket numbers in the lotto machine
 in Higsby's shop in the real world in ACDC area. A little later in the game Higsby will also get a "chip ordering" system for his shop, where you can choose to purchase any chip that you have previously unlocked in your "Chip Library". Some of these chips purchased this way, however, may or may not always have compatible chip codes to be used with other chips that you already have. Therefore, it can be a
little difficult to get the certain chips and matching codes for them that are needed to create some of the Program Advances you may want
 to put into your chip folder. 

 Anyways, aside from utilizing a few other substitute chips just to be sacrificed to use the "Add Chip" function in the custom loadout chip selection screen, until I was able to get all the chips I wanted or needed in my folder at least, the chips listed above are pretty much the
main chips that I always use for pretty much any battle, any boss fight, etc. There are several different strategies that can be formed with
this list of chips. However, the chips themselves are not always going to win every fight for you. You must also take into consideration things such as your own Navi's "style" including it's elemental influence and battle type, whether it is shield style, shadow style, custom style, ground style, etc, etc. Different styles are designed to be used for different purposes and strategies and also when each style is leveled up it will unlock different types of Navi-Customizer programs that can also be used for different purposes. Also, there are other Navi-customizer programs that you will be able to obtain throughout the game other than unlocking them by leveling up a certain style, which can also be very helpful and supportive of your strategy. Aside from all the customizations and navi-customizer pgroams, styles, strategies, chips and program advances, you must also learn to develop your own sense of "Instinct". This means it is always a good idea to save your game before each boss fight, and don't always expect to win the first time every time. Give it a few practice runs, watch them carefully, learn their movement patterns and attack patterns and try to come up with your own defensive or evasive maneuvers, counter attacks, and the best strategies to overcome them. This is actually the most important part of any battle, because once you are able to learn an enemies strategy you will start to fully understand their strengths and weaknesses and it will become easier and easier to figure out how to beat them with almost any chips you want to use, even without having to rely on any elemental advantages. In my honest opinion, the best way to actually become an actual  GOOD Net-Battler, is to be able to overcome a tough situation without making it too easy for yourself and giving yourself any advantage or giving the enemy any handicaps to make it easier for yourself to win. Yes, some styles, navi-customizer programs, chips, program advances etc are designed to make the game a little easier for you, but always remember, the best way to be able to win with nearly anything at your disposal, is to use your most powerful advantage - The ability to LEARN the opponent. You are the player and you are capable of watching, observing, and reading the opponent and figuring out their movement and attack patterns. The opponent's in this game, however, are always going to be pre-programmed entities that always follow the same attack and movement patterns and are not able to read YOU or learn YOUR attack and movement patterns. So with that in mind, you already have everything you need to be ABLE to win just by knowing what to do, but once you know WHAT must be done, THAT is when you will need the proper style, navi-customizer programs, chips, and program advances to use to do it with.

 So with that in mind, test your own favorite strategies, practice, trial & error, etc. Have fun and enjoy the learning experience that this game provides, and share your accomplishments and discoveries and victories with friends and others so we can all learn new things and new methods to try for fun. Thank You.