Gnome Xmonad Lucid
I just got started using tiling window managers because I find that I am a little more productive when I don't use the mouse. With Xmonad, I don't have to deal with overlapping windows and I never have to use the mouse!
I did have some trouble integrating Xmonad into my Ubuntu 10.04 install. I couldn't interface with my wireless card, and I can't always be somewhere with a cable. I had to continue using the NetworkManager app until I had more time to play and look through manuals.
Luckily, I stumbled upon this straightforward walkthrough (Link no longer active). Now I am happily using Gnome and Xmonad in Ubuntu 10.04 Lucid!