PSP in early 2008
Wii in mid-late 2008
PS3 in mid 2009
DS in mid 2010

I've played Wii the most in 2008, then still some in 2009, probably not for more than 20 hours in 2010. I play my PSP from time to time. Not a lot now with summer vacation, same with DS. PS3, play it the most, but still not that much.

360, Jan 2007

PS3, late 2007

Wii, June 2010

PS3 gets 50% usage, the Wii I use here and there, 360 is resting until Halo: Reach. I've been using my PSP & DS most lately and that's very rare. (MGS DQ IX)

->  started the gen as a PC gamer almost exclusively. (big console player before but traveled a lot 2000-2004, so didn't get much opportunity to buy my games... PC being more international)

-> Jan 2005  WoW releases.

->  saw 360 commercials and thought "that's ridiculously soon, this console is expensive and won't have lifespan"... saw 70€ games and said to myself, ok i'm never buying that.

-> Spring 06 quit Wow

-> Summer 06 abroad internship.... bought a PSP to have games with me (and internet browsing).

-> Wii and PS3 arrived, I was sure to buy both, but because of the PS3's price decided to wait for FFXIII... waited on wii also cause I was too lasy to hunt for it.

-> Jan 07  Bruning Crusade releases

-> Summer 07 quit Wow again.

-> Buy DS "for girlfriend" (she actually plays it a lot more than I do)

-> Dec 2007 Buy Wii

-> May 2008 buy 360 for 40€ ...refurbished by MS. i'm never gonna buy this... but it's cheap as hell and I can always resell it.

-> get gaming laptop

-> FF announced for 360.... do I still need a 500€ PS3? nope

-> still haven't bought FF...

-> Nov 09 gaming laptop fries

-> Jan 2010 put 2K in a new PC.... =)

After 7 or 8 games without gaming (I skipped the PS2, Cube, Xbox era), the Nintendo Wii felt attractive enough to get me back in bussiness. That was 2008. A year later, the PS3 Slim release at a lower price got in me in Japan so I couldn't help it: I needed to play Valkyria Chronicles and Uncharted series.
A coupple of days ago I got me a new computer with Mass Effect 1 and 2 and The Last Remnant, which I wanted to play but are Xbox 360 exclusives (well, not really, only on the console market).
Out of the Wii and the PS3, I think I play them quite equally. Maybe a tad more the PS3 now, but that's cause I have lots of wonderful games to complete. A coupple of months ago my time was 100% Mario since I got me Galaxy 2 and NSMBWii together. And I can't wait for the new Metroid, DKC and Kirby. Even less for Xenoblade, The Last Story and Zelda.

I first bought a PS3 and then a Wii.

I have more games and play more on the Wii.

If you count in handhelds:

1) DS

2) PS3

3) Wii

4) PSP

oh usage wise...

PC 50%

Wii 20%

360 20%

DS 10% (my gf uses it too... consoles she does only in coop with me)

PSP ... errr only when I take the train or go on vacation...so overall less than my Iphone :x

2007-ps3 then 2008-bought a 360.  sold the360 and bought a wii in 2008.  2008 got tired of the wii so i sold it and got a psp. sold the psp 2 months later in 2008.  2010 sold my ps3 and bought a ps3 slim.  2010 bought a wii for the wife.  as you can see im very indecisive except for the ps3

Got 360 for x-mas with GoW from my girlfriend, then me and my gf decided to get Wii and mario games.

After that i got PS3 for x-mas from the same gf with Uncharted.

And last month i bought new PS3 slim.

Got DS and PSPgo somewhere between .

Playing:

PS3: all the time (Uncharted 2 online,Killzone 2 online)

Wii: sometimes (all good platformers)

360: not to much (this year only  played a bit off ME2, maybe i will try Alan Wake)

PSPgo: not to much (only if i go somewhere, ill play GTA: CW, tetris and some PSone classics)

DS: not at all (don't even know where it is)

I'll give you an adress in Argentina and you can mail it whenever you want.

Started with 360 on lanch November 2005, but gave that up in September 2007 when my fourth console broke

Got a DSLite July of 2006, sold this later for DSi in August 2009

Bought Wii at the European launch December 2006, still going strong and my primary console. All multiplattform games are bought on this console

bought PS3 September 2009, still going strong