Of all the Linux distros that i have tried(which are very few) I find Fedora Core very interesting.
The basic skeleton of the distribution has remained unchanged since the Red-Hat days. Today I installed Fedora-8 and I can surely say Linux has come a long way. The kind of Desktop themes and eye-candy makes window-vista seem so trivial. Just try out the Compiz-Fusion theme manager. Here is a video in youtube showing Compiz-fusion’s power.
Although I could not get all the effects but I am contended with the cube rotation effect on my Intel Graphic Card.
