Tried Ubuntu as my first just to see what Linux was like , i really had no idea there were alternatives to the windows xp i'd been using since my first introduction to personal computing some 6 or 7 years ago , I quickly got interested in trying others , bit like a kid in a sweetshop i'm afraid , i settled on Mint for a while until the lure of Zorin ultimate and it's look changing ability caught my interest .
I'm still exploring Zorin , as a complete novice to Linux it blends nicely in my dual booted win 7 system ,

Derek.

SUSE Linux 6.4 ... With the YAST ;-) And in parallel a Sun Solaris with the CDE desktop.

Greenhorn
 

This is my first try at any version. I'm running Mint 15 dual-booted with winblows. I had broadcom driver issues with my pci wifi card, got good help from this forum, and had to move the machine to connect with the line to get the drivers and installed, (twice) (:-). I haven't booted with winblows for a couple of weeks now. I am a happy camper.

I got into Linux with the Corel Linux / Wordperfect combination, I had an old machine and decided to try this new Operating System, main point of interest it did work, Wordperfect/wine was slow and kind of worked but Linux never went down. Like most people, my Windows systems were re-booted every day.

Fedora 13. I still have the CD...

First one I actually tried was Slackware, but I couldn't get past the installation (at that time it required floppy disks to be used in some fashion that I couldn't figure out). I gave up and later tried out Mandriva (formerly Mandrake), which was the first distro I successfully installed.

Slackware
 

I asked one of my coworkers about Linux, he recommended I get Slackware. I guess this was probably around 1996, ordered the disks from Walnut Creek, still have them. Now I use CentOS mostly, Slackware for some machines.

redhat linux 8 or 9

slackware 10

Slackware has been my main disto for years. I tried other distros but nothing keeps you away from slack. I believe when you slack you never go back or something like that

My first distro was named Kurumin, one small distro,53mb,with liveCD debian/knnoppix based..., when ubuntu came to Brazil this wonderful little distro developed by tenacious Carlos Morimoto has unfortunately been discontinued ...

Mine was Knoppix...2004 I believe.

This should probably be a different question but I wonder how many people are still using the same distro they first used.
I would put money on those who started with Slackware being the most likely to still be using their first distro, followed by Debian or Fedora.

ALT Linux (Sisyphus)
 

From 1999, I'm using ALT Linux http://altlinux.com , and I've been a developer of it.

It is RPM-based, with APT (as in Debian), and an automated package building and distro consistency testing infrastructure.

http://packages.altlinux.org , http://sisyphus.ru

My first Linux Distro
 

Mine was Slackware 3.5. back in 98. Loved it cept configuring X was a b**ch

Can't remember the first distro I used many years back. It was a mainframe/server possibly running Unix and not Linux. Later came a Red Hat Enterprise machine connected to some expensive equipment. Then a friend gave me a Knoppix boot disk, but I found it too awkward to work from the disk and gave up after a few goes. Finally, the first distro I installed and started playing with was Fedora, and I still use it. It gets my vote.