PS3

360, DS, Wii.

PS3.

DS (x4)/ 3 phats. 1 Lite.: 2005-2007
20 gig Xbox 360: 2007 (sold in March of 2009)
Wii: 2007
PS3: 2008
60 gig Xbox 360: 2009

360 is my favorite. DS is barely used because my kid has taken control of all of them(?), Wii gets a fair amount of use. PS3 is awesome for it's bonus features (browser, Blu-ray, MP3 downloads....).

PS3 60GB was the first, and is now the back up PS3 for playing on the bigger screen (mostly movies and the rare PS2 game).

Wii was purchased second but currently sees no use and won't until Punch Out hits shelves.

Xbox 360 was bought during the Fall of 07 and has not been used to play any new games since Gears 2

PS3 MGS4 LE w/ 320GB HDD sees the most use as the default console and video player. It's quieter and generates less heat than the 60GB.

The non-gaming PC actually sees the second most amount of use for gaming since it's usually on anyway for general purpose use.

The gaming PC sees a bit more use than the Xbox and Wii, but mostly just sits idle looking really big and impressive.

(have a DS sitting in a drawer used to play Advance Wars about a year ago. Forget when I bought it. Early 2007? Late 2006?)

PS3, Wii, and 360 (bought in that order).

I still play my PS2 the most, though. I keep finding JRPGs I never played, in various local GameStops, and despite my PS3 having full BC, I prefer the low power usage of my PS2 (yes, I am that into power conservation, that I will abandon the upscaling for 180W less power usage).  

I will purchase a 45/45nm slimline PS3 the moment I spot one, for that same reason.  If the GC had a bigger JRPG library, I would probably play my Wii all the time.

-Last gen:

PS2, Dreamcast, GBA and Gamecube, sold the Gamecube after a while and kept the good games, now i play them on the Wii

This gen:

-Launch 60 GB Playstation 3 w/ 320GB HDD, remote control, sold the Sixaxis and bought two Dualshock 3
-Launch Wii, bought Classic controller and Gamecube controllers
-DS Lite
-PSP 2000
-Gaming/Multimedia PC assembled by me...

Next gen:

Probably Nintendo and Sony consoles & handhelds, but i don't know...

wii and 360

PS3 PSP AND DSlite.

Wii, DS, 360.