There are some good suggestions here. Its hard to find new stuff that I don't already have. It looks like Gordon Lightfoot and Martin Orford are winners. I also got some Lynyrd Skynyrd. Another friend suggested The Muse. Plus, I downloaded some of the music from the film August Rush.
Please keep them coming; this is awesome.
I was also listening to REM today, which is a great throwback from the 80's/90's.
My favorite "Classical" piece (which I actually think is technically Romantic) is Mars from the Planets Suite by Holst, although Bach has some pretty good stuff. However, you want to talk about old... I have some medievil Organum and Motet choral arrangements which are pretty awesome from just about a millenium ago when 'music' as we know it was being invented.