I’ve used many different flavors playing around… For the most part I use Fedora.
Also have experience with TomsRTBT or whatever it’s called, Mandriva, Gentoo, YellowDog Linux, Ubuntu, Knoppix, Red Hat, etc.
edit: I’ve also used DSL, almost forgot. ( *edited* Small Linux ) – I’d have to give that one props for being the best out-of-the-box.