No criteria other than the above.
Black Crowes - Can't You Hear Me Knocking (Rolling Stones)
Rolling Stones - Bob Wills is Still the King (Waylon Jennings) - Zilker Park, Austin
The Dead - El Paso (Marty Robbins) - Requires context, because the Grateful Dead probably played that shit 1,000+ times. It was at Willie's Fourth of July Picnic. It had rained a little bit and when the Dead came out for the second set, the sky was clearing, and Bob Weir said, "hey check out that rainbow." The crowd turned around and there was a got damn rainbow behind us. Then Willie came out and jammed on the song and when they sang the lyring "Leavin' Texas, fourth day of July," everyone went "whooaoaaaaaaaa."
Ryan Adams - Down in a Hole (Alice in Chains) - Hey, his Wonderwall is great, but this is his cover gem for me.
Galactic - When the Levee Breaks (Led Zeppelin) - This is a fairly common cover for them, but it was in October 2005 and the subject matter was extremely relevant. The singer they had screamed from the pits of hell.