Preparation will need a lot of studies and expensive material, so unless I'm a super-rich like Batman or Iron Man this power is useless.
Precognition: seeing gleams of the future is useless as the main power but good as a secondary power.
Statistic Amplification: this was my initial choice but after reading the description it's useless too, I don't need to boost my combat effectiveness and strength, also since I lack magic or any form of superpower I can't boost non-existing things.
Finally, Probably Manipulation, the best of them both in a fight and in day to day life.