I LURVE linux - mostly because of what it is capable of that no other OS is. I love most distros and have used linux since '92 (i think), in order of use these be:
These days I (personally) mostly use the last 4, though I still play with slackware from time to time, and of course quite enjoy seeing new developments in the linux distro world. Some of the things I have loved include Damn Small Linux, System Rescue CD, Timo's Rescue CD (an old fave), Gentoo and many many many others. There are very few distro's i've looked and said "god thats pointless".
to anyone just getting into this "linux thing", start at ubuntu or fedora and get to know it form the desktop, get on irc on freenode and watch, you'll learn much worthwhile....