I used smplayer before , but it crashes when using the latest mplayer(svn) .
Then i turned to kplayer . There's few video filters , and it stopped updating for a while .
So would you recommand me the best mplayer front-end ?

there's a list of front ends on the mPlayer site http://www.mplayerhq.hu/design7/projects.html

uMplayer looks promising because it's appears actively developed (whereas sMplayer appears stagnant, last update Feb 2010) http://www.umplayer.com/ - never tried it as sMplayer still works fine for me

update: uMplayer is a fork of sMplayer

update 2: tried it and am not having luck with dvd menu navigation (not an issue with sMplayer)