Linux distro's I've used since 1997 (in order): Slackware (2), Redhat (4/5), Mandrake (6/7 I think? Now called Mandriva), Gentoo (too much hard work compiling everything!), SuSE (?), Slackware (10), VectorLinux, Ubuntu (Gutsy to Intrepid) and Arch Linux since Oct 09
I think I'll be sticking with
Arch Linux for ever more, it is fantastic...takes a little while to setup (not like Ubuntu, everything is more manual to define) but it's extremely customisable. I guess you could think of it as half way between Gentoo (hardcore) and Ubuntu (user friendly). It can be extremely fast but it does depend on what you set it up as, I run gnome (same as default Ubuntu) and it is so much quicker than other distros IMHO. The best thing about it though is the rolling release process, no nightmare updates! I update frequently and in small amounts, no 6 month release cycle at all, I got fed up with Ubuntu breaking on a version upgrade and now just run Ubu in a VM for community package builds etc...
To see what sort of stuff I mess with for the community have a look for my threads on ubuntuforums.org, same username as here, I like playing with the Python language and support quite a few conky scripts that use it. Quite the userbase these days, especially using my forecast and music player scripts.
Told you I was a geek
my current desktop (only 2 monitors):