In the order of the list, not in order of my favorites:
1. Denon is great, but I've seen the 4806 and it had some crosstalk issues with HDMI and was very slow with the conversion process. If that follows suit with the 3806, I wouldn't be thrilled - especially if the 2600 doesn't have that issue.
2. Yamaha 2600 - with a track record of excellent receivers in recent years and fast accurate switching, I would wait until the first review came through on the product, then would most likely go that route. They simply make a slightly better product for the money. Good stuff and my vote!
3. Marantz I think is still getting by on a bit of brand name and needs to catch up with Denon, Yamaha, and Pioneer.
4. H/K - not the quality level
5. Rotel - to much money, not enough quality
6. Pioneer Elite - Errmmm... maybe that instead of the Yammie.
7. Onkyo really needs to hire an engineer and test their products.
8. Panasonic - or maybe a Sony? How about a Samsung? Audio please.
9. Nad - See Rotel exclude the quality. Good quality, not enough value for your $$$.
10. JVC - Or maybe a Panasonic?
Just my opinion.