Every Linux (and BSD) user who is currently using Gnome or KDE4 should try Xfce for a week or two.
I've been using Xfce for a couple weeks now, and I can't get over how much more pleasant it is. It's simple. It's unobtrusive. It does what you want with a minimum of fuss. It starts quickly. It reminds me why I use Linux and not a certain commercial OS from a company in Washington state.
I'm now running Xubuntu 9.04 on my desktop machine at work, and I have to say, it's really nice. I take back some of bad things I said about the beta (which utterly failed to connect to any wireless networks on my laptop). The nice thing about having a wired network connection is not having to deal with the disgraceful gnome network manager.
One interesting note about Xubuntu 9.04 is that I have configured it to use nouveau instead of the proprietary nvidia drivers (because the restricted devices manager could not download the latter.) I installed nouveau from the package repository, which apparently doesn't give you 3D acceleration, but I don't care about that.
I had to learn about and futz with xrandr, but eventually I got it completely working with both of my monitors (which are both 1680x1050 widescreens). Here's my xorg.conf if anyone's interested: