If you want to put some energy into running Linux on your desktop I'd say archlinux is the best option: up-to date packages, great support on forums, IRC and wiki, no headaches from constant updating to new versions (a simple #pacman -Syu gives you an up-to date system always), and most of all a great selection of programs both on the official and community driven repositories and also from the Arch User Repository (AUR), if you want to compile stuff (like Gentoo) there is also the ABS (Arch Build System) which lets you compile everything yourself if you have that inclination.

All in all, I can't think of anything that any other distro does better than Arch.

A good first distro would on the other hand be Linux Mint I'd say.