Richard Thompson is a wonderful eletric and acoustic celtic folk-rocker -- an easy to find one is "you? me? us?" which has one acoustic disc, one electric one. "Small Town Romance" is live solo acoustic.
Chris Whitley's "Dirt Flooor" is tasty acuoustic blues-rock
Sharon Isbin's Bach disc is amazing, even better than Segovia IMHO, but partly because the recording quality is so much higher.