Since I'm a Pioneer guy, I'd recommend the Pioneer vsx-1019ah-k. It retails for 500, but you could probably find it cheaper if you check around.

Another idea is to Google for "refurbished receivers". I get a lot of ideas for receivers when I do this. The most popular receivers seem to be (in this order) Denon, Onkyo, Marantz, Pioneer. There are others, but not a lot of mention, such as Yamaha. Some people say that the refurbished units are actually better than the new ones.

As far as sound quality, IMO I think weight has a lot to say about the power supply, but this might not apply much in the 500 and under quality of receivers.

https://docs.google.com/spreadsheet/ccc?...amp;usp=sharing