For those who play, you encounter the first Gym at the 3rd city you arrive it, Sanyou City. There are actually 3 leaders, but you only fight one. The leader you go against will use one of the 3 elemental monkeys that has the type advantage over the starter, which really blows because it is like trying to make a team to go against Brock back in Yellow Version.
I mean seriously, using Physical Attacks against Rock Pokemon is such a cheap move by the game makers. Luckily for us in Pokemon Black/White, a girl east of Sanyou City located at the Site of Dreams will gift you one of the elemental monkeys, specifically the type that will counter the Gym Leader's.
|This is Yannapu, the Grass-Type Monkey|
|Baoppu, the Fire-Type Monkey|
|Hiyappu, the Water-Type Monkey|
All three Gym leaders will have a lvl 12 Yorterrie, which is not too hard to defeat, then depending on the leader, you will face a lvl 14 elemental monkey. Defeat the leader, and you will be rewarded the Trio Badge and TM 83.
The badge looks pretty sleek (don't mind the picture, it's just heavily pixelated), so I suppose there is some visual appeal to Pokemon Black. TM 83 teaches Cheer Up, which buffs both Attack and Special Attack by one level, so great for mixed sweepers and such. And of course, we can't forget that the badge grants you the ability to use HM 01, Cut, outside of battle.