I've been a big fan of Flipside media player for a while now and was even part of the beta testing for it when it launched many, many moons ago. The application has improved much since then and with the BlackBerry internal media player not offering some of the functionality that Flipside can give me I often times find myself using it, more so than the native application.
With last.fm scrobbling, built in cover art downloading and a service called Flipside Extras, which allows you to view artist information and even get suggestions for other similar music that may interest you, Flipside overall is a great alternative to meet your media needs on the go with your Blackberry. A free trial is available in the Shop Crackberry App Store but the big news is that from now up until May 1st you can grab Flipside for only $9.95 (no coupon code required). That's over 50% off of the original price of $19.95. Flipside will run on all devices 4.1 OS+.