Back when I was still a Nintendo snob, I used to go to my friends house to watch him play his Playstation 2, and see what "the other non-Nintendo casuals" were playing. Nothing he typically played would impress me: Metal Gear Solid 2, Tomb Raider Angel of Darkness, GTA III, none of it appealed to me...
Then, one hazy summer afternoon, I came to his house and walked in on him playing as some incredibly-fast white-haired guy that dressed a lot like Vash the Stampede, and was fighting what looked to be a shadowy wolf thing. I asked what he was playing, and he promptly replied: "Oh, it's Devil May Cry. The second one's out, and I want to play this one first."
He let me play for a few minutes, and that short amount of time was enough for me to soak in the sweeping Gothic architecture, the merciless enemy AI, and the mind-numbing acrobatics you could pull off in the game.
I left a few hours later...and I bought my first non-Nintendo console a week later, the Playstation 2, with a brand-new copy of the game that would devour my entire summer: Devil May Cry.