I think you use Windows Media Player and are pretty happy with it?
If so, you'll need some codecs, no way MS can keep up to date with all the new ones
coming out for the media player.
Kevin usually just uses the k-lite codec pack:
K-Lite Codec Pack"Codecs have been a problem for most users at one time or another. This is because there has never been an 'out of the box' working solution that the average computer user could install and just have everything work properly from the beginning."
Windows 7 Codecs Download page About Codecs (If you want to make your own decision):
How-To Geek ArticleI usually use the plain looking KVM player instead of media player, it comes with it's own codec pack.
I'm not sure what's really best for most folks though and since I don't play much music or videos,
I haven't made a decision what I'm going to use on this one though. I know you do and will want to
have it ready to play when you try to play something.
There's a real good itunes player but it doesn't get or put anything on Apple devices.
There's also conversion tools.