I have all of those...it doesn't even matter what console generation you're talking about. Only consoles I don't have are the Sega ones, the Atari ones, Gameboy/Gameboy Color, and the PSP. Oh...right...I don't have the VirtuaBoy either...though somehow I doubt that counts. (I suppose I don't have any off-brand consoles either...but that would almost count against me.)
Xbox 360 and a Wii. I generally play the Xbox 360, but sometimes when I'm feeling nostalgic I'm on the Wii or when I'm playing a game with my family.
If you mean in general I've owned a system from everyone but Sega. Grew up with Nintendo, then went to Sony for some JRPGs and now I'm loving Microsoft's library. Loyal to no man. XD