With the ability to upsample to 176.4, I believe the PS3 to be best of the consoles. The 360 converts everything to Dolby Digital, so I can't recommend it.
A modded original Xbox with XBMC installed would be my second choice followed by the PS2. The Dreamcast was dreadful.
The PS1 stuff ended up being bunk when the thing was actually bench-tested; I still have the "desirable" model in question and it sounds bad with RBCD.