For stereo sound quality, the best 5.1 avr is the Arcam avr 350, without a doubt. You should be able to purchase a used one (maybe even a new one since they don't offer hdmi audio processing) for what you are willing to spend without much effort. Every evaluation I have read and performed my self has shown the Arcam avr 350 to have a leg up on all the competition. However, like I said, this is an older unit and does not offer hdmi audio. You can still get hd playback with analogue transmission. That's what I do and it works just fine.
Best Mainstream Receiver for 2 Channel Audio
I'm looking to pick up a receiver to serve double duty for home theater and 2 channel audio. I'm still unsure how much quality I'd lose from a dedicated stereo preamp/amp or integrated but I'm currently looking at the mainstream brands - Sony, Denon, Marantz, Onkyo, Pioneer, etc. Which make and model do folks here most highly recommend for 2 channel audio quality? Price range would be $1500-$2000.