- There's a huge amount of Ubuntu branding and renaming. I initially paid attention to this after the pretty silent updates that added "Ubuntu branding" to Firefox. I saw a lot of packages and applications that were renamed (or at least represented differently) to make them more generic. Personally, I would rather use the raw software and see the real names for the software packages. Fedora does this a bit too, but to a lesser extent.
- The interface is very polished, but I like having a very raw, stripped-down interface. I generally work quickly, and I can't stand it when the OS can't keep up. I like KDE, and this can be a memory hog, but Ubuntu's additions are even worse, IMO. It was getting harder and harder with each version of Ubuntu to get the interface where I wanted, and now that they're branching away from standard GNOME, I only see this getting worse.
- On that note, I was very unimpressed by Kubuntu, as it had obviously not received the same quality of attention as Ubuntu. As I prefer to use KDE and LXDE, I appreciate the very consistent quality between all the "spins" of Fedora.
- SELinux and hard-drive encryption work out of the box. Again, I'm sure I could get this running just fine on Ubuntu, but it's so much easier with Fedora, so this contributed to me just feeling more at home.
- The kernel had been modified a ton before it got shipped in a release. When I recompiled a kernel it wreaked havoc on some of the software that had previously relied on the added functionality. On Fedora I rebooted into a vanilla kernel and had no problems.
I realize some of these are pretty abstract reasons, but these seem to be directions they're heading more and more, so as I said, I just feel more at home on Fedora, now that I'm comfortable using Linux.