I want to take into consideration things like, native and third party emulators, controller feel and usability, video and audio output possibilities (both naively and with hardware modifications), library availability and quality and of course many things I haven't even thought of yet.
This gets tricky because I love the SNES and original PSX Libraries, but think that the HDMI output and modibility of the Xbox 360 is amazing, but the third party emulator choices and home-brew options on the 360 are lacking which make it not ideal for playing SNES and PSX games.
The N64 is a great console, but lacks good video output without things like the UltraHDMI mod which is very pricey. It's unable to emulate any other consoles and it's controller is less than ideal for any games other than the N64 titles.
The Retron5 is a good choice if you have the 8Bitdo bluetooth SNES/NES controllers, and gives you the options of the Genesis/SNES/NES/GBA and Gameboy and now has IPX support for fan translations and mods, but it lacks N64 and PSX emulation. It's proprietary wireless controllers are not ergonomic and too clicky.
The PS3 is backwards compatible with the PS2 and PSX, but also has great classic collections on it like Sonic's Ultimate Genesis connection, all wrapped into a fairly nice wireless controller with HDMI. There is also SNES9x available for the PS3 which is really nice, too!
Dreamcast is a great contender with VGA support naively, an amazing homebrew scene that is still kicking even today, fairly good library and even some promising emulation options. The controller is not my favorite though and apart from Bleemcast for MGS/Tekken 3 and Gran Turismo 2 there isn't much PSX emulation available.
I probably would have said the original Xbox. When this console was modded on a standard definition CRT it was an amazing powerhouse. All your games can be saved to the hard drive, emulators can run your old NES/SNES/N64/Genesis/Gameboy games. There were some good homebrew games and Hyperspin was a really great way to browse emulated games. Though component video on an HDTV is less than ideal, and there really isn't a great wireless controller options for the original Xbox.
I think I am still working on my favorite console of all time is, but I was wondering what everyone here thought!



