I looked up the Onkyo 505 and it seems like it would do the job, but falls a little short in the number of component inputs (GC, Wii, PS2, XB, XB360, DVD). I was actually looking at the Imact Acoustics switcher, but it doesn't do the older stuff I have via S-Video or composite (NES, SNES, N64, etc)
Of course I could always purchase two switchers, one for component and one for the older stuff. QUOTE]
I suggest using a digital switcher
http://www.smarthome.com/7772.html
for your Wii, Xbox 360, DVD player and Xbox. And then use a composite/s-video switcher for the GC, PS2...etc. You can use the same component input on your receiver for the digital switcher and use the composite/S-video for the others.
You have a Xbox 360 and you still want to have your NES hooked up? Honestly I would get your Xbox modded and get all the NES, SNES and N64 games put on a hard drive to play.