Who Are You Good With?

[Kaden]

I'm interpreting "good" as "would feel comfortable playing in a competitive game against players of relative skill."

Alistar
Anivia
Annie
Ashe
Brand
Caitlyn
Cassiopeia
Corki
Ezreal
Galio
Gragas
Irelia
Janna
Jax
Karthus
Katarina
Kennen
Kog'Maw
Lee Sin
Lux
Malzahar
Maokai
Master Yi
Miss Fortune
Mordekaiser
Nasus
Nidalee
Nunu
Orianna
Pantheon
Rumble
Ryze
Sion
Sivir
Sona
Soraka
Swain
Tristana
Twisted Fate
Udyr
Vayne
Vladimir
Xin Zhao
Zilean

I play some better than others -- I'm most practiced on Ranged AD atm -- but, like I said, I would feel perfectly fine playing any of those champions in a competitive game.