Morgana - mid that can't be counterpicked, worst case you end up in a passive farm lane but morgana is still useful and hard to push out of lane. Wins teamfights with snares, ult and shield.
Amumu - wins teamfights with OP ult, builds really tanky and still deals too much damage.
Singed - if you don't get counterpicked he's a real terror when teamfighting starts and he has decent farm. Bruisers/assasins diving your adc? Fling them away and spray some glue to make pursuing him/her harder. Enemy carry a problem? Ult+ghost, dive him, fling him and run away while half of their team chases you like idiots or continue to poison/fling their carry until it dies if they ignore you. Once you get rilay's you become so annoyingly disruptive the enemy team can't do anything. Enemy bruisers never reach your carry, their carry never escapes you, they never catch you and die from poison if they chase you. --- Still waiting for: Half-life 2: episode 3, Wasteland 2.