Assign Default Media App for all Video Formats?

Hi there,

I would like to know how to be able to assign one video/ media app to open all possible video formats (.mov, .avi, .wmv, .flv, etc)?

I would like all video files to open just in one app, all the time. In my case I use Snow Leopard and would like to assign MplayerX to be default app to open all video formats.

I did try to right click on a video format and "always open with" but it seems only working on a particular file but when i click on another one that is the same video format it opens up with QuicktimeX again.

Any ideas? Thanks