Since no one else has mentioned it I thought I would throw this out there. I use the Vera 2 by Mi Casa Verde and I think its great. Right now you can pick it up for $198 (well, $238 with a $40 mail in rebate from the manufacture). I use it with about 20 z-wave devices (including a schlage door lock), but also my DSC security sensor with 19 zones, my denon receiver, some X10 PL/RF devices, and about four schlage IP cameras that I flashed with different firmware.
It is basically a little embedded device running openwrt with a built in z-wave controller. It provides a very usable web interface and you can extend it very easily with Lua code. You certainly don't have to write code to use it, but the option is there which is nice if you want to add support for new things to your home automation setup.
I was originally going to use something else as my home automation controller and just use the Vera to handle z-wave. But I just really liked the Vera.
I keep hearing about it, and the mention of you Denon receiver interested me. Do you have a Denon with a RS-232 connection on the back, or does the Vera 2 support it via IR?