my top 5 off the top of my head would be:
1. all along the watchtower - hendrix
2. man who sold the world - nirvana
http://www.youtube.com/watch?v=209ArurxVG4
3. hallelujah - jeff buckley
4. pinball wizard - elton john
5. tainted love - soft cell
i left off hurt cause i love trents version