please don't make the same mistake thinking the higher the SPF, the better.
it's actually a marketing tactic and any SPF higher than 50 doesn't really make much of a difference in comparison to the price increase.

also, find a sunscreen that looks matte on the face.
i'm currently using banana boat's sunscreen and i feel that it gets pretty greasy quickly despite the "non-greasy" claim.
also, cream sunscreens over any other type of sunscreen.