Take a look at
www.dvdexpress.com for some DTS titles.
I have a DTS disc ("Daylight", shipped by mistake), and it says DTS on the front...It's got a Dolby Digital Surround soundtrack on it, but nothing else - no extras. I think with the room that DTS takes up, and the mandatory Dolby Digital track, it doesn't have room for anything else...not even Dolby Digital 5.1...which is probably why it's only a Dolby Digital Surround.
I have the Dolby 5.1 version of Daylight now...It is excellent...So if you want to try out DTS, I'd recommend the DTS version of Daylight...but for value sake, I'd recommend Dolby Digital any day.