Even if you don't want a source based system, making one is very very educational. Go to
http://www.linuxfromscratch.org to build your own system from sources. If you can get a LFS system with one of the big desktop packages installed (KDE or GNOME), you'll be very comfortable with compiling , installing, and configuring almost any FOSS software out there.
Yup, it's a huge time waster. 2 weeks for your first system at the very least. But you'll learn plenty. And you'll like terminals too.
With decent 3d support (ATI or NVIDIA card, basically) and a good wine setup, you can run counterstrike on linux.
http://winehq.org/images/shots/full/wine_3.png