A couple of my absolute favorites are:
Dave Matthews Band: The Central Park Concert- Warehouse, Jimi Thing, Dancing Nancies, Cortez the Killer in that order. All songs over 9 minutes and Jimi Thing is 16 min, so you'll certainly get your money's worth.
DMB: Polo Grounds- Jimi Thing and All Along the Watchtower (featuring Santana)
My favorite country song: Toby Keith- Beer For My Horses
other great songs:
Dispatch- The General
Bruce Hornsby- That's Just the Way It Is (might not be the exact title)
David Bowie & Queen- Under Pressure
Clapton: Unplugged- Layla (I think this version is much better)
Sinatra: Don'cha Go Away Mad
Billy Joel- Keeping the Faith (everything else as well
Really if I could own only one album it'd be the Dave Matthews Band Central Park Concert. Just amazing.