I just purchased a receiver (within the last month) I was looking at the 3805, the rx-v2500, and the pioneer elite vsx56txi. There were things I liked about each.
I am a sucker for more badges and certifications, so I liked the THX on the Yammie and the Pioneer (the Pioneer also has EQ tuning in music modes from AIR studios - George Martin of Beatles production fame). I realize that primarily THX is a certification for acheiving certain output, but I have also seen that there is some post-processing tuning that comes with THX.
I also liked the USB and firewire inputs on the 56.
I liked the possibility of bi-amping my front speakers with the 3805.
When I auditioned all 3, I realized that I would be happy with any of the 3. They really were great. I thought I could tell a slight difference in the soundstage bewteen the 3, but I wasn't able to conduct A/B blind tests. After I saw that I would be happy with any of the 3, I took RLA's advice, find the features that are most important to you, and then choose by remote interface.
I didn't care for the Denon remote, even though it looks cool. So I narrowed it down to the vsx-56 and the rx-v2500. The rx-v2500 can be had on-line for around $700, while the 56 is always around $1000. That canceled the 56. Then I realized that I could get everything I liked on the 56 except the USB and the Firewire (which I really, really wanted) on the 54 for the same price as the 2500, plus I could bi-amp my front speakers.
In the end I went with the Pioneer Elite vsx-54tx. I am very happy. I got THX certification, AIR studio tuning, the ability to bi-amp my front speakers, and a very simple remote. Even though I had never programmed a remote before, I had all of my electronics promgrammed into my remote in less than 15 minutes (probably less than 10 minutes really). Plenty of power, very happy