I will be a Dragon type because Dragon type Pokemon Are strong . Also I will have three Pokemon Dragonite , Garchomp , and Flygon.

More than likely, I would he a grass type leader. I like the Grottles, Turtwigs, and the such. Or, if possible, an all around gym leader. I usually have a grass, lightning, water, dragon, ghost, and some other type with  me, so I would an all around gym leader.

I would be a fire type gym leader I would have a charizard,arcanine,and ninetales all three have balanced stats

There are a lot of type i would like to be so i'll list them all. 
I would be a dark type gym leader. I would have Sableye,Honchkrow,Tyranitar,Hydreigon,Sharpedo One for every region (except kanto cause they have none).
I might also be an electric type leader. I would have Electabuzz,Lanturn,Manetric,Luxray,Galvantula One for every region
I would be a fighting type gym leader as well. I would have Hitmonchan,Heracross,Breloom,Lucario,Sawk One for every region.
I could also be a fire type gym leader too. I would have Flareon,Houndoom,Camerupt,Magmortar,Darmanitan One for every region
Lastly I would be a Steel type. I would have Scizor,Aggron,Metagross,Empoleon,Bisharp

i would either be a grass gym leader with speedy pokemon like shiftry and sceptile and maybe a venusaur for power

or a flying type with staraptor skarmory and mandibuzz

or a fighting with pokemon with 2 types like infernape and gallade and lucario

or finaly an ice type with glalie, wallrain and some other ice tyypes

i think ice types though

Now even though bug is probably my least used type of pokemon, there's one advantage I can think of a non-generic team, (as a gym leader rarely uses a full team I will use only 5)

I would use dual type bug pokemon,

1# Armaldo,
Second type: Rock
Moveset: Aqua Tail, Low kick, Metal claw, Ancient power.
Item: Leftovers.

2# Scizor,
Second type: Steel
Moveset: Iron Head, Night Slash, Aerial Ace, X-scissor.
Item: Scope Lens.

3# Volcarona,
Second type: Fire
Moveset: Fiery Dance, Hurricane, Bug Buzz, Solarbeam.
Item: Wise Glasses.

4# Galvantula,
Second type: Electric
Moveset: Discharge, Bug Buzz, Sucker Punch, Giga Impact(as a finisher move).
Item: Wide Lens

5# Shedinja,
Second type: Ghost
Moveset: Shadow Ball, Heal block, Metal Claw (from is pre-evolution), Final Gambit.
Item: Rocky Helmet.

No contest, I'd form a normal gym. Most normals have average to great stats in one or two areas and only fighting can be super effective. Of course, this is lessened by the fact that they only resist ghost (completely). Added to their strengths is that most normal pokemon can learn tons of moves from tm's. 

Since most gyms have short teams, I'll pick four. 
1) Kangaskhan
2) Zangoose
3) Ursaring
4) Snorlax

I went for a bulky attack squad.

There hasn't been one Dark gym, so i'd be a Dark gym leader. Zoroark, Scrafty, Shiftry, Houndoom, Hydreigon, Sharpedo... so many possibilities!

I would be either a Dragon type gym leader or an Ice type gym leader because those two types are the most epic types there are (matter of opinion fire is the second best)                                                                                                                                                                                                                                                                                                                                                                                                
 

     The Pokémon i would have for the Dragon gym would be the following
     
          1.) Flygon
          2.)Dragonite
         3.)Altaria
        4.)Salamence
                                                                           
                                                             
   For the Ice gym i would have
            1.)Froslass
            2.)Lapras
            3.)Mamoswine
            4.)Glalie
                           

Hmm I would have to say either a normal type gym that holds double battles because I know a few great strategies
My team would be a Blissy with toxic in its move set, a Ditto, a Porygon-Z and a Sawsbuck.

I would be a dragon type leader because dragon types have very few weaknesses and they can learn TM moves like ice beam, flamethrower, thunder bolt, and surf, and some can learn solar beam so what ever type you use,dragons most of the time (well my dragon types) have the advantage in a tight situation.

I would definitely be a Fire-Type Gym Leader. I have always favorited Fire Pokemon from the very beginning. Choosing from Kanto Pokemon only, my team would be Charizard, Magmar, and Arcanine.

I would be a fire type gym leader, I really like fire types like Charizard or Arcanine.  They're powerful and have great attacks. 

I would be a random gym leader.
my pokemons would be:
rayquaza(shiny=D!)
armaldo
tyrogue(out of he's pokebal like pikachu from ash)
mew
regirock
hitmonlee(wild, a hitmonlee that followed me from the start of my journey and started to became my Pokémon )

I have 223 post I'm glad I finally hit the 200 post counts I'm lucky iv been here for only 61 days.

I would be a ghost/dark type gym. There hasn't been a two type gym before, and Sableye is beastly