demonoid.com is the only general one I use, if you're after specific types of things (apps/tunes) etc then you're best off finding a specialist torrent site that just deals with that kinda stuff.

Demonoid.com is invitation only though, um, think I may have an invite though if you want to drop me an email (click on my avatar).

Edit : I don't mind, I have invites to places sitting unused anyhoo.