You must be a very strange person. If you have the power to do anything you want, why make life any worse for other people you've never met?
If I was godlike for a day I'd give myself around £10 million pounds. £10m is big enough to get me going and is low enough where id'd still want to be much richer. The great thing about being given it in one **** would be that I wouldn't have felt as if I earned it, so wouldn't be as frightened to lose it - as say someone who has spent 30 years slowly accumulating such wealth. I'd go about trying to turn my £10m into a billion, a bit like playing Football Manager but giving yourself a little transfer boost with a data editor at the start of the game. Whoever dies with the most money wins.