Splinter Cell. I don't own one yet, but that was the first 360 game that continues to make me go "I need a 360 for this". Fable and Mass Effect had their share though.

Well, I actually bought a 360 to play both Halo and Gears, I have always been a shooter and adventure game fan. But I recently bought Mass Effect 2 , kinda on a fluke. I had seen the trailer on the game and talked with other people that had played the first one, who loved it. So I bought Mass Effect 2 used at the game store for 45 dollars, knowing if I did not like it for a week I could return it for my money back. I have never played a RPG, and also Playing my PS3 mostly, so I started Mass Effect 2 and absolutly Love it, I have to say I think its my favorite game of all time, the best game flop I have ever bought, So then I went back to buy the first one and they were sold out, so I went home and bought it in XBL, Have not started it yet , but I will when I am done with Mass Effect 2. So far I have about 30 hours in , but I am new to RPGs and I am doing everything I can in the game to prolong it as long as I can. So I really love my 360 now, and I still love my PS3 but it just has had a nice long break to rest untill God Of War 3 comes . If there are any other games like Mass Effect 2 I will lile a lot for eathier 360 or PS3 Please let me know by a message . Thanks

Call of Duty Modern Warfare 2...

How do you forget to put the call of duty franchise in there.

I bought reflex and then thought it was absolutely amazing so I decided to play MW2 and bought the 360...I got Halo 3, GTA IV, Blitz(came free), NHL 09, SVR09, RAW 2(XBOX Original), COD: WAW and finally MW2....

Halo for me, though I knew that some off my other favorite series like Fable and Splinter Cell would be coming. Add to that the adverts for Bioshock and Mass Effect that came out around that time and it was a no-brainer.

I wanted to upgrade into this gen and seen a real good deal on the 360 so bought one. It wasn't any game that did it as I have owned a console from every gen so I was going to get a HD machine regardless.
I did get Gears with my 360.

Got a 360 when they did a price drop a month before Halo 3 came out, but I did pick up Gears and Viva Pinata when I bought my 360 which I both loved.

Halo and Fable made me buy it on release. I knew those games were coming anyway.

I never thought I would be able to play GTA IV, Resident Evil 5 or Final Fantasy XIII. That was just a bonus.

Halo!

dirkd, I may have misjudged you. I seriously thought you were a Sony only guy, I apologize for pigeon-holing you, even if you didn't know I was.

^traitor in a different way....whatever i am a traitor by buying the 360 last week for MW2....I have been a proud Ninty-Only supporter until the last week or two in which my wii has rested as i was too busy playing Mul;tiplayer plus I have lots ofprojects and tests....also multiplayer is what I bought MW2 for but after playing till the cliffhanger level and after passing the snowboard part of it...just damn!!!!!!!!!!!!!!!!!!!!!!