Comment: Re:Awesome WM (Score 4, Informative) 357
This.
I actually liked Unity very much, but in it's latest installment it became a sluggish PITA, so I started looking for alternatives. After using lxde-dekstop on the existing Ubuntu for a bit. Then I scratched that and started to build a complete custom install on the basis of the ubuntu minimal install CD.
So now I use lightdm, awesome wm with xcompmgr for basic drop shadows, Ambiance themes, Faenza icons and everything Ubuntu has to offer in the way of clear, smooth font display. Only gnome-settings-manager and gnome-keyring are left from Gnome Desktop.
This is the snappiest, fastest and most usable desktop environment I've worked with so far. I use it on my work notebook, with two 90 degree tilted external displays, and everything works without a hitch, even switching from rotated displays to the notebook screen and back (thanks to xrandr -o and disper).
It's geeky and a bit of a learning curve if you want to customize, but I'd definitely recommend giving it a try.
(And - on a DE unrelated note - if you work with code everyday tilting your display and seeing the code over the full _length_ of your monitor is like a breath of fresh air.