Andrew Bird - Oh Sister (Bob Dylan)
APC - Imagine (John Lennon)
Bauhaus - Ziggy Stardust (David Bowie) - I love David Bowie, but Bauhaus outdid themselves with this cover.
Dynamite Hack - Boys in the Hood (Eazy E)
Fiona Apple - Sally's Song
Heather Nova - Wicked Game (Chris Isaak)
Ingrid Michaelson - Can't Help Falling In Love With You (Elvis Presley)
Save Ferris - Come On, Eileen (Dexy's Midnight Runners)

I like both Cohen and Buckley's Hallelujiah above any others. And Hurt by NIN is better than done by Johnny Cash.