I wasn't happy with SUSE, (though YAST was nice) so I'm using Fedora 15 at the moment. I'm a little miffed at Fedora's philosophy of often including bleeding edge software, but it works fairly well. I've come to value customizability, ease of use, and reliability over speed, though.
I used to be 100% ubuntu (after having tried 15+ distros, I liked how ubuntu was the best supported with new things, there's much to be said for a large userbase) and I used to run it for 104 days at a time (the exact amount of time between school starting and thanksgiving, when they make us go home) which was pretty cool.
I was really liking SUSE, but the fact that many of the programs I liked to use (my fav. LATEX editor, GNU octave, etc.) required herculean amounts of configuration to make work, I eventually gave up, and ordered a FC15 disc from the local fedora fanboys.
This has been working acceptably well for my 'everyday' OS, though due to the nature of my webbrowsing habits, my laptop needs more RAM.
My favourite portable one is crunchbang, which has some useful things preinstalled, and fluxbox makes it run nicely. I did have to change it up to add Dvorak layout to the handy keyboard switcher app, though.
Then, I have a used mac pro (I got it, and 2 G5's for a total of $80.) that I popped my windows HD into for gaming, and emergency non-linux use (mostly using software that won't run in linux, I'm also too lazy for emulators). It runs well, though my graphics card won't work in the EFI, or OSX (not that I'd use it anyway. There's really no benefit of me switching to OSX/hackintosh)
Finally, I'm setting up a samba server for backups, I'll probably use ubuntu server or some such (any suggestions? I set it up all over SSH, which was pretty cool. Don't need no GUI), since I did it before, and have most of the work done on one of my harddrives. I was surprised that HP (the OEM) put 6 HD slots into one case, almost as much as I was to learn that it was in the e-waste pile, and therefore free for me to take.
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The mac pro will probably get some more use this winter, as it's a crazy space-heater.