There is a big difference between "Cheap" and "overpowered". People keep mentioning powerful stuff, which isn't the same thing.
Cheap abilities are one that do stuff like win quickly and easily even against people a lot more powerful than you, generally by bypassing the normal way of doing things.
For example, Scorpion-Carmilla Black is, at most, slightly enhanced physically due to having all the toxins and such cleared out of her. But she has a poison hand, which can potentially one-shot all kinds of people, once absorbed part of a Venom symbiont (while still being deadly to the touch of the original!), and can be amped by giving her stronger poisons to process up to insane levels. Any poison, pretty much any amount, she's good.
Or, Squirrel Girl. Sending squirrels against Thanos or Doom is just *cheap*.
Originally posted by Lord Feron
Easily Blink... she isnt really all that amazing except she can teleport you chest to the moon if she wanted to...
The EXiles have several cheap abilities. Blink can kill just about anything if she gets creative and mean enough, and Nocturne's possession is also really cheap, she leaps into you, uses your body, and can fire energy bolts from it. And if she leaves? You're asleep for 24 hours, even if you're Wolverine.