KDE seems surprisingly decent now (I tried Plasma out the other day).
Personally, I'm still using Unity 7 on X11, but as that DE's project is now seemingly dead again, I keep looking for a replacement. This one also looks pretty interesting!
I would really like to find something that handles fractional scaling as efficiently as Unity/Compiz. That, the dash, and (I'm ashamed to admit) wobbly windows are what keep me using it.