For less than $600 you can get a NEW Onkyo 705 shipped free from amzon/vanz. All the latest converting/processing. Exc a/v performance with a solid 100wpc and 7.1 capability. Otherwise, for 5-6 bills I would recommend looking for a used Emotiva setup.
HT Receiver recommendation
Little by little I am upgrading my modest home theater. Just added an OPPO HD980 DVD player based on input from this board. I still have a (gasp) Yamaha Pro-Logic receiver, so I think it is now time to upgrade the receiver. I have pretty good Paradigm speakers all around, and need at least 100 watts/channel and at least a 5.1 unit, and I use a 42" Sony LCD TV. I am hoping to spend less than $500 on a used unit. I am thinking Denon, Yamaha, Rotel, Sony ES or something similar. I am really a 2-channel guy, but enjoy movies on a decent system with my family. What would you recommend?...and, thanks in advance.