We can debate console sales until the cows come home but who is really winning the console wars? Well, it turns out none of the current generation of consoles has taken the top spot. Neilsen, famous for their TV ratings studies did a study on game use. They measured the total number of minutes people spent playing games and divided them up by percentage.

According to the study, gamers spent 42.2% of their time with the Sony Playstation 2. Here's the ratings from IGN.
Videogame Console Usage (April-November 2007)
1. PS2 – 42.2% of usage minutes
2. Xbox – 13.9
3. Xbox 360 – 11.8
4. GameCube – 7.1
5. Wii – 5.5
6. PS3 – 2.5
7. Other – 17.1

This only includes TV top consoles, not computer games (which I believe would likely rank top spot if that were factored in), or handhelds.

This certainly says something about the PS2. I remember the excitement over it when I was in Grade 10. Hard to believe that was seven years ago and still harder to believe its still going. As past history has show, consoles usually die a quick death in key markets (North America, Japan, Europe) when the next generation comes out. In fact, all sixth generation consoles are still holding strong, with the Xbox 360 being the only well used seventh generation console.
Also of note is the fact that the Wii ranked so low in time used despite it selling like hot cakes.

Source: IGN