I have a few HDCD's, and really liked the idea of it. Sadly it all seemed to disappear when Microsoft bought it.
I remember being excited by my Rotel 951 CD player being compatible, and being very excited when the little red HDCD light came on with various discs. One HDCD disc I often used for demo purposes was 'Spirit' by Jewel, and in particular the track 'Down So Long'. My girlfriend is sick of that track as it was always the one I used when tinkering with my hi-fi!
There used to be a definitive list of titles at the Pacific Microsonics site, but it seems to have been pulled. I think there are various lists out there that might be found from Google. The only thing to be wary of is that some of the lists are incorrect, in that they list albums that have HDCD 'flags' which light up HDCD lights/logos on players, or show as being HDCD in MS media player, but they actually have no HDCD content. Also, there are albums that aren't all in HDCD, just some tracks, and these are rarely listed.
Every time I find a list, I find albums that I want, but I can never track down the HDCD versions. Norah Jones and Michael Buble both have HDCD albums that I'd like to get, but I rarely find them for a sensible price.