It's too bad I can't remember My best team. It destroyed just about everybody. It was in Pokemon sapphire. None of my friends could beat me.

Edit: I found a better party.

Pikachu: 47 Thunder, Thunderbolt, Body Slam, Surf
Mew: 47 Fly, Psychic, Bubblebeam, Tri-Attack
Primeape: 47 Rock Slide, Dig, Low Kick, Strength
Kabutops: 47 Slash, Cut, Water Gun, Ice Beam
Raticate: 47 Ice Beam, Super Fang, Quick Attack, Water Gun
Butterfree: 47 Mega Drain, Psybeam, Flash, Confusion

I beat the elite four and my rival the first time through with this party. oh and I didn't cheat to get Mew I used the glitch.

my best was probably...

feraligatr lv. 100

lugia lv.79

amparos.lv.70

seaking lv. 60

sneasel lv. 58

weedle lv. 3 for my entertainment!

I like to do a lot of range with mine because moves seemed to overlap. I hated having a team where two of my pokemon had pretty much the same moveset. Only downfall is that if your grass type gets knocked out and you needed it to finish the battle, you'll have to figure out another way to hit them where it hurts. I did a lot of variety with my teams, though try as I might, I was never able to pick just one dragon.

This was my team from Pokemon XD:
Breloom - Grass/Fighting (With Effect Spore)
Houndoom - Fire/Dark
Starmie - Water/Psychic (With Thunder Learned)
Altaria - Flying/Dragon (Possible Swap for Salamence or Dragonite)
Dewgong - Water/Ice (Knowing Mostly Ice with possible swap for Froslass for Platinum)
Flygon - Ground/Dragon

Altaria and Flygon were probably the greatest tag team I've ever had. With Flygon knowing Earthquake and Altaria remaining unaffected every time helped me sweep through tons of battles. Shame that they pretty much went to shambles against Ice Type.

And I agree with earlier users. I'm not much of a fan for using legendaries, though I do like Jirachi and Celebi. If I was able to get them without cheating, I'd probably have them on my team because they can be pretty badass.

my best party from emerald was

swampert:lv72
crobat:lv71
gardevior:lv70
aggron:lv71
manetric:lv70
flygon:lv70


EDIT: I erased your layout here, because it was messing up the thread

Hmmm well I'd have to go and say it would be either of these two sets.

Dragonite level 100
Cyndaqual level 70
Moltres any level
Psyduck level 80+
Spearow level 60+
Vaporion level 80+

And this my all time favorites
Dragonite level 100
Charizard any level
Ditto level 90+
Haunter any level (just to laugh)
Articuno any level
Espeon any level over 70

My best ever (undefeated) 6 Party Pokemon was in my Yellow Version.
I had All level 100's! Pokemon included Pikachu, Golem, Pidgeot, Charizard, Mewtwo and Omastar! Now if only I can find my Yellow version cartridge.

Shuckle level 100 sandstorm, protect, toxic, rest
Shiny ho-oh level 100 sky attack, earthquake, sared fire, reflect
Dewgong level 100 sheer cold, ice beam, dive, aqua tail
Sceptile level 100 leaf blade, leaf storm, frenzy plant, strength
Crobat level 100 u-turn, sludge bomb, fly toxic
Absol level 100 sucker punch, night slash, perish song, me first


THEY ARE UNDEFEATED!

In Soul Silver I got a Milotic, Lucario, Garchomp, Crobat, Alakazam, and shiny Typhlosion (shiny Typhlosion does not look cool on pokemon battle revolution by the way).

it really depends for me, mine is tied with pokemon firered team

[pikachu, blastoise, charizard, bulbasaur, golem, alakazam, gengar.]

and my pokemon heartgold team

[typhlosian, pikachu, noctowl, golem, totodile, bayleef]

i didnt put in the teams with the legendary pokemon.