Time, Gravity, and Reality based powers tend to be the most broken and abusable.

Mostly because they manipulate everyone else, instead of just the user. 

Self contained gravity, reality, and temporal powers however.

I love those.

Able to alter how much you weigh, able to alter your speed, so on and so forth.

Edit: Forgot to mention 'Energy' as one of the most broken and abusable. Mostly because that falls into the hole of Nonspecifics.