Xbox 360: Bought it in anticipation for Halo 3 and to play Halo 2 with a friend.
Glad I bought it because of Fable 2, Left 4 Dead, Fallout 3, Elder Scrolls, Bayonetta, and Bioshock.

PS3: Bought it in anticipation for God of War III.
Glad I bought it because of Vanquish, Batman Arkham City, Portal 2, Valkyria Chronicles, and Rayman Origins

Nintendo DS: Bought it because it was nintendo's next handheld. duhhh
Too many games to list that I was pleasantly surprised with.

DS - Got it on launch, because I knew I would get it anyway - Best handheld ever made. Bought all 4 DS models.
PSP - Got it when it got hacked - Really great handheld, but had it not been hacked, I would have had very little intrest.
Wii - Got it on launch, because I knew I would get it anyway - Nintendos worst home console,but still decent. The hacking is scene is amazing.
360 - Got it when the GoW bundle came out in Europe - Hate Live, but otherwise decent console. Wish they had never made Kinect.
PS3 - Got it when GoW3 came out - Broad selection, and a decent console, but much like the Wii, this is Sony worst home console.

To me, the "7th generation" has been all about handhelds, while the home console has been largely dissapointing. Too much flash, too little game.

Ps3- killzone 2, MGS4, DMC4, RE5, FF13

Glad about: Demons/dark souls and blazblue (plus the revival of the fighting game in general)

360- lost odyssey, vesperia, ninja gaiden 2

Those are still the only three games I own for it

wii- Smash bros, zelda, RE: umbrella chronicles (before it turned out to be a light game)

Nothing, a big disappointment. Even a lot of nintendo games were sub par

psp- A variety of rpg and tactic games

Exactly what I expected. Killzone liberation was a nice surpise

ds- Advance wars dual strike.

Various rpg/tactic games

Vita- Gravity rush/persona/Killzone/ Dragons crown

Glad about project diva/team ninja + games

wiiU- gonna get for monolith soft x, bayonetta 2 and FE x SMT

PS4- 4th should be just as good as the last 3

DS= Bought for Pokemon Diamond, well worth the money.

PS3= Bought for PES 2010, ender up buying more game and glad I have it. (God of War Saga is well worth the money by the way.)

DS, kinda bought it for backward comp. to be honest, wasnt really interested in the library per se. I only ended up getting like 6 games for the 5 years I had it. M&L BIS and TWENY were excellent though. Not sure it was worth getting a whole system for though.

PSP, my initial one was actually a present, I wasnt impressed with the system and still wasnt until GTA came out for it, then it was all uphill from there. LCS was better than 3, TWO full Metal Gear Solid games, a better version of Tekken 5, Crisis Core, a great update of FF Tactics, playing PS1 games on the go, two Star Oceans, BETTER than arcade perfect fighting games on the go. I couldnt ask for more.

Wii Got it for Smash and first party games and whatever unique 3rd party games that were coming. Cant say im glad I bought it, Brawl was the one of the biggest let downs ive ever played in my life. Right up there with FF13 and KOF12. IMHO i felt the entire 1st party efforts were lacking minus Galaxy games. They just werent as good a prior console libraries. Not even going to get into 3rd party as we all know how that went down. ANd the one game I did spend alot of time playing (GE) ended getting a better version on HDs anyway.

PS3, got it for Tekken6, MGS4, FF13. Goes without saying im glad i bought it, ironically its because of the games I DIDNT buy the system for. Didnt think Uncharted would be as good as it was. Loved the whole fighting game resurgence. It more than made up for some of the letdowns, like Tekken6(not bad but not better than 5) which was ok because Tag2 is better in every way. There is enough JRPGs released and ones coming that I dont even really care if we actually get Versus. And i enjoyed games I thought i wouldnt, ME, Fallout etc.

DS - Bought For Zelda and Metroid Prime Hunters.
- Glad I bought it for (with caps) THE WORLD ENDS WITH YOU. Also Elite Beat Agents was awesome.

360 - Bought For Halo and Xbox live.
- Glad I bought it for, Mass Effect, Gears of war, Lost Odyssey, Bioshock.

PS3: Bought it because of Metal Gear Solid 4.
Glad for pretty much every game franchise I've played on the PS3.

PSP: Bought for Kingdom Hearts Birth By Sleep
Glad for Crisis Core, Dissidia Final Fantasy, MGS Peace Walker

PS Vita: Bought for Gravity Rush
Glad for Uncharted Golden Abyss, Assassin's Creed II Liberation.

Wii: Bought for SSBB
Glad for Wii Sports (serious)

NDS: For future Pokemon games
Glad for Super Mario

X360 - Bought for Halo 3, glad I got it for Gears of War, more Halo games, Tales of Vesperia, and the multiplats that ran and looked better than on PS3.
PS3 - Bought for MGS4 and Ar Tonelico 3, glad I got it for Uncharted, Tales of Xillia 1&2, Atelier series, and ton of other import RPGs.
DS - Bought for Jump Ultimate Stars, glad I got it for Advance Wars, Fire Emblem, Super Robot Wars OG games.
PSP - Too little interest, did not buy.
Wii - No interest, did not buy.

PSVita - Bought it out of impulse really, as a powerful portable. Glad I got it for Persona 4 Golden, Hatsune Miku Diva f, Ragnarok Odyssey, Ys Celceta, Zero no Kiseki Evolution, upcoming titles, and the few PSP games I had an interest in (mainly Falcom).

PS3 bought for FF 13 // glad for demon's and dark souls

PC upgrade bought for Diablo 3 and Starcraft 2 (both of which turned out to be crap) // glad for Alan Wake and Dolphin the Wii emulator !

That's a great sales pitch !

Wii - got it for Godfather, Wii Sports, Tiger Woods, Brawl, Mario Kart

Glad I did for: Lara Croft Anniversary, Dewy's Adventure, PoP:FS, Wii Fit, NSMBW, Wii Sports Resort, Mario Strikers, Fire Emblem:RD, Sakura Wars:SLmL and especially Endless Ocean & Endless Ocean: Blue World

Been very happy with Wii.

360 - Mass Effect, Dragon's Age, Bioshock, Burnout Paradise - all of which disappointed me.

Glad I did for Batman AC