Hmm...that one is always changing for me. I guess I really have 2 lists, one is an "at the time" type of list, the other is current. While a console may have had a massive impact on me at the time, it may no longer be a favorite.
"at the time"
-NES
-Playstation 1
-SNES
The NES got me into gaming in the first place...I learned how to play on the thing, I have to give it it's props for that. The PS1 was a machine that I just devoured games on. I spent more time on my PS1 on the 90's than I did any other. The SNES is damn near right with the PS1...1991-1994 was owned by that machine. I was never a Sega guy. My era of current title heavy gaming pretty much died after 2000, it was at that time when I began exploring oddball systems like the Neo.
Systems now? That's a completely different story.
-NES
-GameCube
-SNES
-Genesis
-PS2
This is literally the order in which I game at the moment. NES being the most often, PS2 being the least. I no longer own many other systems and the ones that I do own that didn't make the cut, I never play. I no longer own a Neo basically because what titles I really liked on the thing, I have on comp sets elsewhere.