I'll try and give you links to great mash ups as I find new ones. Right now there are so many, it's unbelievable the amount of quality tunes.
Check this out by LeeDM101
(amazing mash up producer)http://soundcloud.com/leedm101/leedm101 ... monday-newFissunix
gives Heartbreaker a new wrapping. Funky! http://soundcloud.com/fissunix/hitzbreakerThe Reborn Identity
works out a nice dance tune to the tune... of Fleetwood Mac. Really nice! http://soundcloud.com/rebornidentity/th ... girls-likeDJ Zebra
is back. This time with an absolute knock out- New Order meets The Stoogeshttp://soundcloud.com/contact-227-2/10-blue-dog