SuSE 6.1 was my first Linux distro but at the time (must have been around 1998) I never got it to working the way I wished. Basically I was scared off by the effort to find my way into configuring the system on a "text-file-editing" basis being an AMIGA user since 1989 and fixed on a more GUIficated approach.
My first "working" installation (meaning working satisfactory according to my needs) was a SuSE 8.1 and I've stuck with SuSE ever since. ATM I am runnning a SuSE 10.0 on a 6-year-old Mitac notebook, a SuSE 10.1 on a three-year-old Uniwill notebook and openSuSE 10.3 on a DELL Vostro 1500 notebook and on my workstation (self-built). All of them have a parallel installation of Win XP pro exclusively for gaming purposes.
My first attempt to install and see Linux: Red Hat 5, around 1999, on a 486 DX4.
My first working Linux: Corel Linux
My first operative Linux: Mandrake 9.2
Since then, ever Mandrake/Mandriva as main home desktop since 2005LE. Tested some Suse's and found them slower that Mandy, Ubuntu (found slow startup, don't like the sudo approach and I'm not a GNOME fan, poor KDE support), PCLinuxOS (fine, but poor Spanish language support), GoboLinux (?) and Gentoo (mmhh, maybe someday will give another try, then I had only a 256 KB ADSL).
Conectiva linux 4.0 was my frist try.(Conectiva+Mandrake=Mandriva), later I tried:
Red Hat 6.2
SuSe (don't remember the version, was the stable one in 2002, 7.0 I guess)
Debian 3.0 woddy, and I felt in love since then!!!
Today I still use Debian ;-)
my first linux contact was in 1995 with Slackware v3.0.0 (kernel 1.2.13); first home server was a RH 7.1 and first production server was a Slackware 8.1 (mail+web server, kernel 2.4.18) in y2k
most used distros were: Mandrake 8.2, Slackware 8.0 and 9.1, SuSE pro 8.1 and 9.3, Debian sarge 3.1 and etch 4.0, most used kernel versions were 2.2.19, 2.4.18, 2.4.29, 22.214.171.124, 126.96.36.199 and 188.8.131.52;
also used for a while Debian potato 2.2r7 and woody 3.0, Corel Linux, few Knoppix's, Mandrake 9.1 and 9.2, Slackware 3.5 and 7.0, Turbo Linux 7, Yoper 3, SuSE pro 7.1, 9.1 and 9.2, SimplyMepis 2004 and 3.3 and some Slack derived: Slax, Vector, Zenwalk, Wolvix...
now I'm stuck on Slackware 10.1 (home desktop+home router), OpenSUSE 10.3 x86_64 (alt. home desktop) and CentOS v4 (office server/router)... don't like *buntu's and Fedora
My first was Ubuntu 6.10 back in 2006(yeah, I didn't even know about Linux until 2005). Right now I'm using Ubuntu 7.10 and will probably keep using Ubuntu for a while. Tried Fedora 8, but couldn't get wifi to work, so I uninstalled it after some hours.