lagvoid, I'd try Mandrake 7.2. It's by far the easiest to set up and "mess around" with; and though I've been a SuSE user since the 4.x series was released, package maintenance (installation/upgrading/removal) seems to be geared primarily toward Red Hat-based distributions, so you won't have to worry about having things installed in "strange" places.
Both SuSE and Mandrake are RPM-based, but for ease-of-use and for a gentle introduction, Mandrake 7.2 really can't be beat. If you're a bit more "on the edge," however, and willing to tinker more, SuSE 7.0 is a great candidate as well. I'd hold off on 7.0, though, since 7.1 is due "anytime"...
Definitely don't get vanilla Red Hat 7.0; quite a few things are broken, and since I'm a developer, I can't stand broken development tools. =P