UMPlayer is a new cross-platform SMPlayer fork. Since it uses Mplayer, it can play most video formats and comes with some very interesting features. For instance, it supports CSS skins so it's very easy to theme.
I've updated UMPlayer to revision 143 in the WebUpd8 PPA - this update brings a feature many have been asking for in the comments: the time position in the video is now remembered (thanks to Steve for the tip!).