What operating systems do you use?
I've been using Slackware (-current, since 14.2 is old 'n busted). It's a comprehensive distro, their implementations of KDE and XFCE are rock solid, and almost everything seems to "just work" for me. It still feels like BSD, but without the inconveniences.
What, if anything, would sell me back on Linux? :)
You've got to decide that for yourself.