Check out the Foo-Fighters cover of 'Baker Street' (originally by Gerry Raferty) . . f***ing great song, given the full Foo treatment.
also, i reckin Weird Al Yankovic deserves a mention for his ever so slightly tinkered with covers . . . . things like . .
1) Pretty Fly For A Rabaii (originally preety fly for a white guy by offspring)
2) FAT (originally BAD by wacko jacko)
3) GUMP (originally LUMP by the presidents of th USA and yes its all about forest gump!)
4) Omish (spelling?) Paradise - Originally Gansters Paradise by Coolio
all hilarious and there are far too many to mentione them all . . if u wanna larf check it out via kazaa or what ever your chosen medium