I'm a fan of "This Could Be the Start of Something Big", which is the first track on The Great Kai & J.J..

It's very upbeat and lively, and is recorded very well. Actually, the entire album is excellent, but the first track in particular is my favorite, especially as a demo-worthy cut.

Anything off of J.J. Cale's "Troubadour" sounds amazing, if you want upbeat blues (although not really 'jazz')

Junior Wells's "Mystery Train" on Telarc label.Available both on cd and sacd.

"Tomorrow's Girls" and "Teahouse On The Tracks" from Donald Fagen's Kamakiriad. The DVD-Audio in 2 or multi-track is astounding. The CD ain't slouching either.

"The Best of Randy Crawford" is one of my favorite cds as a demo.
Two songs, "Rio de Janeiro Blue" and "Cajun Moon" are both beautiful and well recorded.
Randy has an amazing voice and is backed on this cd by Joe Sample, Jeff Porcaro and Steve Lukather among many others.