Very interesting thread! :-) I too buy a lot of DVDs from DeepDiscountDVD.com and Amazon.com. I try to get the DTS version whenever possible. But DTS DVDs are becoming more and more scarce everyday.

4 M80s/VP150/EP600/Denon AVR-5308 & DVD-2910/
2 QSC SRA3622(1100wattsX2)/Carvin 1800HD(600wattsX2)