I finally coughed up the dough and invested in a Playstation 3 for The Last Guardian... if that ever comes out (hopefully next year, we can only cross our fingers).
I bought a 360 for the GTA IV Episodes/DLC. Ironically enough, I could've just waited about a year and bought the DLC on PS3 instead, but too late. Love my Xbox anyway.
If we're going back further, I bought a PS3 because my PS2 broke and the last backwards compatible PS3s were still in stock. Got Heavenly Sword because I needed a cool God of War type game to go along with my shiny new console.
Bought an original Xbox for Dead or Alive 3, a PS2 for NBA Street of all things, a GBA for Tony Hawk 2.
I got my 360 for Gears. Kinda funny because I completely lost interest in vanilla shooters not long after. Got my Wii for Twilight Princess. It's mostly gathering dust now. Got my PS3 just because I wanted to have all of my bases covered. My PC must always be kept up to date. I also got a 3DS to replay Ocarina of Time. Kinda regretting that purchase now. Hopefully that will change soon.
PS3 - MGS4, Heavy Rain and Bluray sold it for me.
Was huge fan of Fahrenheit (Indigo Prophecy) when it came out for Xbox. There were really no other games like it, so i was sold on another game like that.
Last game of the Metal Gear Solid series, how could you not want to see how it ends?
I didn't get my consoles for a specific game. No one game, IMO, has been enough reason to buy a consol for. The reason I got my 360, was purely due to the dramatic death of the original Xbox. And plus it was a gift... I didn't get my PS3 till late 2009, when there was around 10 or so games that I really wanted.
I bought my PS3 for MGS4, Ratchet & Clank Future and Blu-Ray.
I bought my Wii for Nintendo franchises.
I bought my 360 (which eventually broke and I didn't care to replace, prompting me to buy a PS3) to own a console from this generation, although probably for Halo.
Sega Genesis - Don't remember
N64 - Turok and Mario Kart 64
Xbox - It was a gift from my cousin. It was a total surprise too since I didn't have any real desire to get a new console, but I wasn't about to let a gift like that go to waste so I played Max Payne which was part of the gift.
Xbox360 - Halo3 I guess since I had already played Halo and Halo2 on the Xbox
Wii - Zelda: Twilight Princess, Metroid Prime 3: Corruption (+ any other major 1st party Nintendo game)
PS3 - BioShock, Assassin's Creed, MGS4, Final Fantasy Versus XIII (hahahahaah ........ :/ )
Xbox 360 - Alan Wake, Mass Effect, Banjo Kazooie: Nuts & Bolts
Bought the Wii at launch, a PS3 in 2008 and the 360 in 2010 when the Slim version launched. Originally, I was gonna buy a 360 instead of a PS3 mainly because of BioShock and Alan Wake but then they announced they were porting BioShock to PS3 and that was enough for me to go with PS3 first (also, all my friends are Sony fanboys and thus only had PS3s).
I have a 360, a DS and a Wii at the moment, but although there were certain big titles on those systems which encouraged me to get them, I didn't buy any of them for a single game. Consoles are expensive and I could never fork out the money for one just because I wanted one game they had. On the Wii though, I was encouraged by Wii Sports, Mario Galaxy and Zelda: Twilight Princess, with the DS Super Mario 64 and the new Pokemon were pretty big factors and with the Xbox 360 I was after the Halo games and Viva Piñata among other things.
Xbox 360 - was going to wait for Halo 3 but then saw Dead or Alive 4 and got it much earlier
Wii - Monster Hunter Tri
DS - Advance Wars: Days of Ruin
Gamecube - Super Smash Bros. Melee
N64 - Super Mario 64
Playstation - Crash Bandicoot
_I don't remember for the following
I am 19 BTW
I bought the PS3 for MGS4....
I bought my 360 years ago because I hadn't fully switched over to PC as my main platform by then. So when I feel into some money I still had the old mentality of needing to own every system and I ended up buying it because I didn't have enough for a PS3 at the time; plus that was back when the PS3 was a barren wasteland. My PS3 I bought for all the exclusives and a back catalogue of PS2 games that I never got around to playing.