Just got my copy of UT2004 Special Edition, and it is very impressive. In the box, you get 2 DVDs. The first contains the game, Maya PLE with UT2004 plugin, KAT for playing with the physics, and UPainter for model painting. The second disc, a dual layer DVD, has 8 gigs worth of tutorials covering every aspect of content creation, including machinima. So, if you have a slight tingle to build something in a game, this is a great cheep investment to start out.
And it's not a bad game either :-)
Best Buy has all of this, plus a headset for voice chat for $30.