Mostly hi quality CD's (MOFI, Audio Fidelity, DCC), some hi quality vinyl. Some K2 mastered CD's sound great (ELP, Eagles), some not so great (Bat Out Of Hell), probably depends on how good the original master was. Have a couple SACD's and an older OPPO DV-981 that I haven't listened to very much. Bought a Sony CD changer and recorder in 2006 - it makes a bit for bit copy of any original CD, so my CD's only get played a couple times to make copies to use, mainly in my vehicles.
Mark