My experience from a HTPC perspective...
Denon 3806: Great recevier, served me well. HDMI went out in early 2013 and then left channel went out in late 2013.
Onkyo 818: Currently in use. Great receiver as well so far although I haven't tested everything on it. Some intermittent issues with handshaking especially if I don't let the projector fire up and wake up the HTPC before turning it on.
What are you using? What have you used?
And as an aside do you have any recommendations in the ~$500 range?