Nunu is great especially if you take champions along that scale well with attack speed. Like Diana, Kayle, Jax, or one of the few viable AD carries on TT like Quinn, Ezreal, Caitlyn, Vayne.
Cassiopeia is also damn scary in TT. Strong laning phase and 1v1 and will make the enemy paranoid about facechecking anything. She also shreds through Vilemaw. You can still build her relatively tanky thanks to how her E works. --- LoL EU West: Sabrewylf
Jax is one of the best snowball characters on Twisted Treeline. Shen is not so good on any random team combination, but a coordinated duo of Shen and Singed can be a nightmare for opponents to lane against. Fizz is also incredibly good. Xin Zhao can almost guarantee a gank around level 3-5 in top solo lane if your opponent just barely screws up. Miss Fortune I have had a lot of success with strangely enough on Twisted Treeline, but it may have just been people who played really poorly in those games. Teemo can absolutely destroy people that don't try to get Oracle, but only if your opponents are dumb like that. If they are remotely good then Teemo can't work too well. Renekton is also ridiculous in lane similar to Summoner's Rift. Just insanely broken during the laning phase since as soon as he gets 50 Fury and is level 3 or so if you get within range he can take off at least half of your health and put himself within melee range of you almost instantly. Kayle is incredibly good at snowballing on Twisted Treeline, but she does not have as high of snowball potential as other characters like Jax or Fizz do. However, she is never a bad choice and can be great on a variety of teams and you can generally have good success with her. --- Good game design died when people began to think having to use outside sources like guides to get past mandatory parts of games was acceptable. - Chipsrgood555