Red Hat Linux, Fedora Core, Fedora, MythDora, CentOS and Red Hat Enterprise Linux.
Long version of it:
There were a set of Red Hat Linux 5 CDs sitting at work - let me back up first - A buddy at work had played with Linux a little, but he was still a PC tech at the time doing printers and desktops, and I'd moved over to doing Novell and Microsoft server stuff for work and some Cisco work, but basically we were living paycheck to paycheck, living in studio apartments and no real spare PCs to dink on (each of us just with a PC and a dial-up modem).
I'd been tasked 6 months or so ago when I was a lowly PC tech to clean out this storage room. I'd found this PC, in an IBM AT case (with the big red switch power supply on the right side), that had been sitting there forever. The service tag was very old, and if I recall right, the person who had dropped it off didn't want to pay for the work or whatever, so it was just sitting there. I asked if I could have it, but was told that the customer might still pay for it (yeah right). I ask if I could put a Post-It note on it with the date or something saying I could have it in 6 months. "Sure." So 6 months later, I had a spare PC - 486 DX4-100 with like 4mb of RAM. These were the days of Win95, but this piece of junk had Win3.1 or something on it.
Where I worked had just opened a new office in a bigger city just north of our HQ. One of the things we offer was ISP services to commercial accounts - T1s and nailed-up (always connected) ISDN. We had some BIND DNS servers that had been installed at this office, but I wasn't in charge of them and couldn't touch them. But sitting on the desk by them was a set of Red Hat Linux 5 CDs.
I burned a copy, and my co-worker and I installed my first Linux install on that old 486. I'm pretty sure we didn't even install the GUI (storage and/or RAM limitations), but just CLI. We got Apache and an FTP server working on it.
Great, but we only had dial-up at each of our places. But by that time I was helping maintain the ISP side of things. I think I was stuck recabling and cleaning up the 3 racks of gear we had late on a weekend. I snuck the old 486 case in to one of the training office cubes and put it on the floor, wired up power and ethernet, and told the gal there to be quiet about it and it'd help keep her warm (that office had a bad HVAC setup and it was late fall / early winter). So I gave the Linux box ("Artoo") a public static IP connected to the public ISP switch, and that's how things started.
A little bit later one of the senior server and network engineers gave us two sticks of 8mb RAM (we're still broke these days), and we were able to get the server up to 20mb of RAM. I think about then we started running an IRCd and MUD game, payed $70 to register artoo.net (back when NetSol was the only game in town, and you had to pay for 2 years up front at $35/year). We started hosting domains for friends and family... it was an amazing time and we learned a ton.
We were so lucky too. We used plain auth for everything, including just telnet. Our setup was small enough and we were lucky enough that even with no firewall and horrible stock default settings that we never got owned for that first year.
Sometime during that first year the service center assistant manager (no kind words for him) was having problems with his PC. He blamed hardware, said he'd swapped all kinds of stuff out, and still it was flaking out on him. I asked if I could have his old desktop as he'd just gotten a new one from inventory (they build custom beige boxes). He smugly replied, "sure, but it's just going to keep locking up on you."
I don't recall if we just took the hard drive from the old 486 or if we reinstalled, but basically we got our same setup going on that "new" Pentium 166 (32mb of RAM?) and we just kept learning and hosting more and more. This was still on RHL 5 (probably 5.0, but I don't know, and didn't know anything about updating originally).
We kept getting used parts - but now it was out of retired servers and we had a SCSI controllers and hard drive or two (in the end we had 3 drives in the bays, and two drives sitting on card board at the bottom of the case). I started to earn better money, got nailed-up ISDN at my house a perk with my position, and started adding RAM to the server, eventually maxing it out to 196mb. About that time we really scored and got an old server, which became our second server, "threepio." This allowed us to start doing upgrades without downtime - we could move sites around change DNS, wait for TTLs to expire, and then do work on the original servers.
Anyone remember cheapbytes.com? They're gone now, but I believe we bought unofficial RHL 6 CDs from them.
RHL6 is where we started doing upgrades, but since we didn't have subscriptions it meant we continued to buy the upgrades from cheapbytes.com. We moved to RHL 7, 8, and 9. About that time I actually started convincing customers to use Linux instead of Novell Groupwise or Microsoft Exchange. They'd buy boxed RHL with subscriptions, and we'd set up sendmail and whatever the pop3/imap daemons were in those days. That was a pretty cool time for me - making money with Linux skills (instead of just my Novell CNA and Microsoft MCSE skills).
I'd been dual-booting my work ThinkPad (another nice perk, as otherwise I'd not have been able to afford a laptop) with RH7 & then RH8. But when RH9 came out, I went all in an wiped the drive except for RH9. I was doing almost all Cisco by this time, so I didn't need Windows for most things - we had Citrix servers to remote into and do our time sheets and other corp-specific work. I stuck with RHL9 well after EOL (never had subs anyways), but eventually tried out FC1 at home. I recall it broke a few things - Apache 2 didn't work the same, etc., so I stuck with RH9 until FC3 came out and was found to be really stable (FC2 had big issues as well, so I skipped it).
Everything was upgraded to FC3, and then I continued to skip releases, but partly because I went to CentOS releases based on Fedora release. FC3 to EL4, then FC5 (MythDora somewhere in here for my TV PC) FC6 to EL5. I've kept on EL5 for the majority of my servers. EL5 was getting long in the teeth for desktop, so I went to F9. I skipped F10 except for the MythDora release, then went F11, F12, F14 to EL6.
There are times I'm tempted by Ubuntu or something else (and I check them out briefly in a VM), but I've never installed a distro that wasn't RH-based (RHL, Fedora, RHEL/CentOS) on bare metal. I'm pretty happy for the most part. I just want things to work, and I don't dink nearly as much as I used to. The Fedora releases always annoyed me because of the short lifespan and constant install. At this point I'll probably be on CentOS for a long time - however I nearly jumped ship to Scientific Linux 6 with the very long CentOS6 release delay.
But right now I'm very happy with RHEL6 at work and CentOS6 at home.