In no order, other than what #1 is....

Since I've Been Loving You - Zeppelin
Prayers for Rain (live, Entreat album) - The Cure
Empty Room (unreleased, 1995 version) - Prince
Summertime - Janis Joplin
Round Here (live Pinkpop, '97) - Counting Crowes (or does this belong more in a Best ****ing Live Performances Ever thread?)