tried xubuntu 8.04
its great

installed mplayer to test
it cant play rmvb/rm at first
codecs need to be installed

I downloaded "Binary Codec Packages" "Linux x86 20071007" in http://www.mplayerhq.hu/design7/dload.html
so it is http://www4.mplayerhq.hu/MPlayer/releases/codecs/essential-20071007.tar.bz2
and placed all files extracted in /usr/local/lib/codecs/

but rmvb still can't be played
the trick is to download "all-20071007.tar.bz2" inside http://www4.mplayerhq.hu/MPlayer/releases/codecs/
not from the download page link in mplayers official site