Marantz is still on top I think, at least in the sub-5K price range, but if you're going to buy one, spend the extra--- I'd stay away from any new receiver in the sub-1K range-- Marantz offers one that is under 1K... but at that price point it just won't have enough quality in terms of the insides. For a receiver, heavy = good.
I'm running a Sherwood Newcastle R-865 and I love it. It was 2.5K new, weighs a ton and has the cleanest sound I've heard. Before getting this receiver I was partial to Onkyo. I still like Onkyo, but now know there's better out there.
You can get a Marantz or Sherwood Newcastle very cheap online if you're willing to buy used. Because the R-865 doesn't do HDMI switching, you can find them in great condition for under $500. I'm sure equivalent deals are available for older Marantz receivers. You would never get equivalent sound out of a new receiver that retails for $1K.
Denon is good too. I would stay away from Yamaha (too complicated to run, though good quality) and HK (they seem to have gone too mass market and I think quality has suffered as a result).
Edit: Wow look at this for $1400
http://ca.marantz.com/Products/2419.asp#
That would probably sound better than my Sherwood... prices have really come down.
2nd Edit: Hmmm... that Marantz rated at 110w is 1/2 the weight of my R-865.... I take that back.