DS: Haven't used it in 9 months
PSP: Used it briefly a few weeks ago when I finally figured out custom firmware and some emulators, but it's collecting dust again
Wii: Picked up SimCity on VC and Trauma Center Second Opinion a while ago, so I'm actually playing the damn thing every now and then.
PS3: Super Stardust HD almost every day. Virtua Fighter 5 all the time too. And SF3 Third Strike and Marvel vs Capcom 2 and Silent Hill 2 and SOTN and God of War 2 on PS2/PS1 BC (Silent Hill 2 and Third Strike look awesome upscaled to 1080p with smoothing

)
X360: Bioshock demo, over and over again.

Also replaying DEAD RISING and a little bit of Gears. Been playing with Third Strike on Xbox1 BC too, want to play this online but the slowdown bug really sucks, I hope MS fixes it soon. Also been playing Fight Night 3 a lot too, that game is still fun 18 months later, hope FN4 comes soon and delivers the goods too. Also Pac Man CE and SF2' on XBLA to kill time now and then.
My time break down is something like:
45% X360
45% PS3
9% Wii
1% Portables
Of my time on X360, I spend about 65% on 360 games and 35% on Xbox1 games
Of my time on PS3, I spend about 45% on PS3 games, 50% on PS2 games, and 5% on PS1 games.
Of my time on Wii, I spend about 35% on Wii games, 25% on GC games, and 40% on VC games.
Putting it into perspective, PS3 and X360 get daily useage, often more than an hour a piece. Wii gets weekly useage, usually about an hour or less per session.