A couple I can think of:
Best
Arcade Fire - Guns Of Brixton
Original by The Clash
Tom Hodge - Aerodynamic 
Original by Daft Punk
The Ukelele Orchestra of Great Britain - Dy-na-mi-tee
Original by Ms Dynamite
The Killers - Shadowplay
Original by Joy Division
Jonsi - Time To Pretend 
Original by MGMT
Dragonette - The Boys
Original by Calvin Harris
Florence + The Machine - You Got The Love
Original by Candi Staton
Noisettes - When You Were Young
Original by The Killers
Sugababes - Freak Like Me 
 Original by Adina Howard also heavily samples Gary Numan's 'Are 'Friends' Electric' on that note...
Original by Adina Howard also heavily samples Gary Numan's 'Are 'Friends' Electric' on that note...
Moloko - Are 'Friends' Electric
Original by Gary Numan
Blondie - The Tide Is High
Original by The Paragons
Maxence Cyrin - Where Is My Mind
Original by Pixies
Maxence Cyrin also does amazing covers of D.A.N.C.E (Justice), Around The World (Daft Punk) and Windowlicker (Aphex Twin).
Finally... The Vines - Ms. Jackson
Original by OutKast
I didn't think I'd end up with this many!
The only bad one I can think of is Razorlight's cover of 'Hey Ya!' by OutKast, it just sounds so messy and is really dull in general. They also used a gospel choir but it didn't add anything, just made it sound worse :/