If you truly want a versatile player, I would go with VLC then. It pretty much plays anything you can throw at it and would definitely look into it. It also has conversion, video effects, among NUMEROUS other capabilities you won't find in other players. And it's FREE That's my 2 cents anyway. There is also another freebie I picked up that is like Power DVD and such but just doesn't look as pretty, it called Movie Spot.
Links below...
Code:
http://www.softset.ro/moviespot_en.html
Code:
http://www.videolan.org/vlc/
Hope that helps them a bit