Good FreeWare games anyone? List your top 10 or 5!?

I am really bored and i need your top 5 or 10 freeware games (and where to download them will be great)! They dont all have to acctually be "free" though. PLease dont include anything that wont work on an old computer, cave story (already have it) or noitu love 1 or 2 (have both). Thanks!!!!