I don't consider myself a fanboy, but I am obviously biased towards SONY. I shifted from the NES, SNES and Gameboy to the Playstation brand and have never looked back.
Don't get me wrong, Nintendo consoles were superb back in the 90s, but in my opinion it all started going downhill starting with the 64, and even more apparent with the Cube. I grew up with Nintendo, have very fond memories of my childhood playing all those games and nothing will ever change how I feel for the first 3 consoles. I still play them to this day. The rest is a different story.
The Xbox I respect and concede that it is in some ways superior to the PS3, but in my opinion it's no match to the PS3.
The Wii... well, no comment.
Voted Sony.