Here are a few to get things started:
Don Henley’s The Boys of Summer as an 80s synth tune
Bossa nova version of Crowded House’s Don’t Dream It’s Over
Reggae-ish version of Aretha Franklin’s Respect
A capella men’s ensemble version of Lady Gaga’s Bad Romance
EDIT: This has been great, everyone. Thanks to everyone for all the terrific links and for introducing me to a number of artists I wouldn’t have heard of otherwise. Seriously, the online rabbit-holes have been thoroughly enjoyable–even it I stayed up a bit too late a number of times.
Worth it.
Disturbed’s cover of The Sound Of Silence is so much better than the original.
and the Conan performance is the best performance of it (that can be easily found), the studio version doesn’t have quite the same vibe.
Thank you for mentioning this! I just listened to it and it gave me goosebumps. It’s a brilliant cover.