I've never played it - is Devil May Cry a pretty popular game? What does its sales numbers compare to?
Not sure about it's sales figures, but it's an action game with a gothic-monster theme. Dante is the son of a great hero who has perished. He owns a freelance shop where he takes care of any demons/beasts that anyone asks him to handle. You go on a quest to figure out what exactly caused your mother's death after a woman comes in telling him some information concerning it. That's the first game.
The second game, to me a disappointment, is a giant filler for lack of better term. The story has little to nothing to do with Dante, however the action is still as fun as it was in the first one and you also get to play as a different character: a bird-woman whose name escapes me.
The third game is a prequel to the first, revolving around Dante, his brother and their history that leads up to the first game. I haven't played this one but I hear it's incredibly difficult. I can only assume the action in this is as badass as I've heard it is.
The series is great fun, with flip tricks, guns, swords, transformations and acrobatics up the wazoo.