Debian vs Ubuntu vs Fedora

Debian = stable, just works, no commercial support, takes years for releases (I use that for my work machine because I don't want to update every 6 months)

Ubuntu = Less stable than debian, 6 months of testing vs 2-3 years for debian, commercial support (I use that on my laptop because I don't use it often and I need new drivers)

Fedora = bleeding-edge, newest stuff, not for production, no commercial support ( I use that on my dual-boot home pc, since I don't really care)

Each have their own purposes, Debian for serious work, Ubuntu for more update yet stable stuff, Fedora for living on the edge. Hope this helps.