I tried Mandrake 10, I didn't think it was as mature as Fedora.
Plus, fedora abandoned X11 for the more advanced x.org. All the windows are graphicaly accelerated and the redraw is awsome. I use Gnome on it, and it is the next most beutifull OS from OSX.
As a matter of fact its probabbly the clossest thing to OSX on a PC I have ever used
Yous should totaly try fedora.
P.S. If your a C/C++ programmer, you should check out the Adjuta IDE for Gnome. Its a fantastic development environment, and it's free.
Quite honestly, I don't understand why Microsoft is still around with such fabulous free alternatives.