Fedora 22, but by September I'm going to decide whether to stick with Fedora or switch to something else, maybe back to an LTS release of Ubuntu or CentOS. (most likely going to get F24 when it comes out though, I don't really mind that they go through the numbers really fast.)

Yeah, kinda agree to that, though I think it's still more of a matter of how people feel about it. I personally like how hardcore they go with their software, releasing a lot of programs that just don't quite feel finished (Builder, Boxes, etc.)... Keeps reminding you that they intend to take things up a few notches.
Sad thing is the downside of that is I see them phasing out some good software I use, just because they're old. For a while, I've been using gEDA packages for a while for some simple electronics work (I forgot on Ubuntu or Fedora, probably on both at some point), but they decided to get rid of them from the repos and bring in this Qelectrotech thing, which feels 80x more clobbered together than gschem. Then again, I heard of some devs just stopping work on their software, like video card drivers.
Maybe eventually I work on creating custom distros for the machines I work on, and if I get bored enough, I MIGHT just look for an 8-bit version of the kernel for AVR chips