[gladimdim]

I also gave a try to XFCE 4.8 on my notebook with 1Gb RAM. I cannot say that it is lightweight. It took about 15 seconds to start XFCE. I also spent about 20 mins doing usual job on it and then uninstalled it. That is why I use pekwm.org . It is ultra-small, fast and light. Actually XFCE is environment and PEKWM - window manager. No additional functionality like panels, quick launchers, trays etc.

For me LXDE stays betwen XFCE and PekWM. It is not so heavy as XFCE but PekWM is lighter.

[sigzero]

I like the lean and mean window managers as well (fluxbox at the moment).