I have tried a number of players, but certainly not all of them. Each has had good and bad. When it is working BSPlayer is the most flexible and universial player.
I am constantly having to reload BSPlayer, codec's, re-setting key definitions etc. But when it works it is wonderfull.
PowerDVD is much more limited, but seems to be equally more stable. But there are some files it just refuses to play. The player from DivX, Zoom, MS Mediaplayer all work with some files, but not all and lack the range of features BSPlayer provides.
The most frustrating aspect of the entire movie watching experience is finding the codec's needed. Here are two threads that helped me;
http://forum.bsplayer.org/viewtopic.php?t=3042 http://forum.bsplayer.org/viewtopic.php?t=3331
I also found this codec package that seemed to work well for most things;
http://home.hccnet.nl/h.edskes/finalbuilds.htm
Good Luck