DSOTM is definitely next on the list. I'll be getting Yes' Fragile at some point, I use to play that album over and over and over...
I'd consider Machine Head, but there's not enough on that album to shell out that kind of cash for a few songs. Although I bet 'Space Truckin' would sound awesome in MC (multichannel)..
Maybe Rumors someday, but classic rock radio stations kinda put that album to a slow death over the years for me. In the same vain, I haven't broken down and bought Hotel California, though I did get their HFO DTS DVD. I've considered Seal's Greatest Hits, he's got a great voice and I'd probably like it, but I haven't listened to his stuff extensively. Maybe Elton's GYBR, I'll bet Funeral sounds awesome in MC, too. "brown dirt cowboy", now that's funny..
I picked up a 5.1 (not hi-res) dvd of Beethoven-Symphonies 7 8 9 with the SWR-Sinfonieorchester (orchestra of Baden-Baden and Freiburg, I think) which is in 4:3 video format, but it is an excellent recording of his 9th symphony, which I'm a huge fan of. I recently saw they have an SACD for the Amadeus soundtrack, which I'd grab in a heartbeat, but I don't think it's MC. Doesn't help that it's around $40, either...
-TD