Kass is definitely the best..DUNKS all.

Aside from what's been mentioned.

You can run an AP Udyr build focusing phoenix damage and AS/On-hit.

You can also run Skarner as an AP/AS-on-hit. People tend to give me grief for it, but his kit really leans toward having a healthy amount of AP and his passive just gets better and better with more AS. Lichbane with his Q is great dmg in general and you can sheen down towers like mad early-mid game.

OMG MASTER YI. ap he gets pentas with ease

Poppy, Diana

Mordekaiser. Hue hue hue.

Fizz. Totally Fizz.

fizz...i highly recomen him he is just awsome

I suggest fizz, akali, and lux.

Lux wasn't mentioned at all in this whole entire thing, and I am surprised. She has a great ult for picking up kills and has a binding and a slow for escape. She even has a shield, so she is useful in team fights.

Akali has INSANE burst damage, and has a good escape that also stealths. She also can use shadow dance to close ALL gaps.

And I think you have heard enough about fizz XD