Fudge is a good game for beginners. I've GM'd several Fudge Games in different settings over the years, and I like the game a lot. The Action System is also good (and the core rules are free.) I don't know if FUZION is still around, but it was free, and people had posted supplements for it all over the web.
No matter what system you use, the best supplements, in my opinion, are GURPS supplements. They have tons of them, for every genre. They tend to be very detailed.