"Conduits Technologies, Inc. announced today the release of Pocket Player 3.6 for Windows Mobile 6 Standard, Professional and Classic devices. Pocket Player aims to satisfy consumers who demand more from a media player on a mobile device. Pocket Player 3.6 includes new improvements to the library and media browser, as well as many fixes to core functionality and plugins. Pocket Player is also compatible with Windows Mobile 5, Pocket PC 2003, and Smartphone 2003 devices."
I have never tried this one before, have any of you? It looks pretty good and there is a 30 day trial available. You can purchase it here as well for 19.95USD.