100,000: Get myself a nice car and save the rest (read: squander on useless shit like games)
1,000,000: See above, replace car with house and car
10,000,000: See above + more "saving"
100,000,000: Buy a small village of houses for my family
10,000,000,000: Buy a small town and name is MR SOOTYVILLE
100,000,000,000: Pay the ransom to Dr Evil and save the world. Then watch him go nuts with the money and destroy everything.