One of the 500 features included in the Mango update included that ability to import custom ringtones on your Windows Phone. We've already touch on how to get the ringtones on to your Windows Phone. We've also looked at a few of the ringtone apps available on the Marketplace (Pimp my Ringtone, 1,777 Ringtones and Ringtone Maker (which isn't really a ringtone maker)).
The last piece of the puzzle, so to speak, is that a decent collection of ringtones are being gathered over in our Forums. In this discussion, you can find ringtones from Kid Rock, Dean Martin, Beastie Boys and Metallica. You can also find Homer Simpson and the theme from Rawhide.
All you need to do is download the attached file, make sure the genre is "ringtone" and import it to your Windows Phone (through the Zune software). The tone will appear in your Ringtone and Sounds settings as custom.
If you've got a favorite ringtone you'd like to share or one your looking for, feel free to join in on the Forum discussion.