Not all of the *nix products out there are equal, but if you're looking for a relatively easy install, or you want to run a partitionless install, however slow, to just get your feet wet while you're taste-testing, I'd recommend Red Hat Linux 7.1. Easy install, and you get to try out all the 'toys' without jeopardizing your existing OS. When you're done trying it out, or when you're ready for a full blown install, just delete 2 simple files, and reclaim all your HDD space.

Just my 2c worth...

Verdure