This one, to me anyway is much faster moving than the first one. They didn't have to spend any time setting up the story and explaining what mutants are or introducing characters. They pretty much just dove into the story. There's more action in this one, a few explosions, a flood, and a chick named Lady Deathstrike. If she weren't a bad guy, she'd be Wolverine's ideal babe, but it's just not to be. The "bad mutants" have to team up with the "good mutants" in order to get the better of a guy named William Stryker who is trying to kill off all of them. Mystique gets a lot of screen time in this, and Rebecca Romijn even shows up (without the blue!).
A fun ride, teaming up with bad guys, making things blow up, and generally wreaking havoc, but of course, as it must, all comes round in the end. (For the most part.)