alistar. good luck trying to get him off his lane. even if it's a 1v3 you wont be able to take his tower without getting cc'd all the way to hel and back. dont even get me started on how hard he punishes towerdivers. alistar is generally played as a roamer, but i like laning with him so i can babysit a carry.
nunu is infinitely better as a jungler, he has little pushing ability and survives through actual creep contact, which is extremely easy for an opponent to deny.
another powerful laner is malphite. get a malph with doran's shield and clarity and you could get your 2nd bloodthirster and he'd still be in lane.