Rrsupercharged: cash did an absoljtely fantastic job with hurt. That entire album is full of great covers.
Currently my favorite covers are:
Puscifer : Rocketman ( rocketmantastic)
Playing for change: gimme shelter
Playing for change: redemption song
Playing for change: imagine
The basis behind playing for change is amazing. Every musician was recorded in a different part of he world. None of them ever met before doing he songs.
There are far too many to mention, as I'm a really keen music lover and bedroom DJ I know of far too many to add here, but some personal highlights for me are as follows:
30 Seconds To Mars - Stronger
(A truly stunning rendition, which can chill the spine in the latter half of the track. This is a remake of that god-awful Kanye West,"cashing in on the shirt tails of Daft Punk's success" track.)
Orkidea - Unity
(The original is by Dead Can Dance - The Host of Seraphim. Orkidea's version builds on the great foundations that DCD's original presents and escalates into a hard-driving trancer that was a firm favourite with Paul Oakenfold back in the day)
Bjork - Pagan Poetry (Infusion Remix)
(An all time favourite. The thing about this remix is,,, well, just about everything! It's a breakbeat builder, heavilly laden with trance, that actually makes Bjork's cooky voice seem perfect. Whilst the original has all the elements of the remix, the addition of the pitch, beat and bassline make this version an ultimate.
Infusion aren't very well known, and most people who hear this version automatically think it's by Hybrid, down to the lengthy breakbeat intro sequence and the rolling basslines.)
Special mentions also for U2's Even Better (Perfecto Remix) and Delerium's Silence (Tiesto Remix)