Why the first X-Men movie is still the best ...

It's about the characters, stupid.

Look. A film's only 2 hours long or so. It's not a serialized comic book which can go on for hundreds of issues. You don't have that much time on screen. So you have some choices:

Spend a lot of time with a few characters, and get to know them well.

or spend a little bit of time with a lot of characters, and don't.

X1 made its choice: this is a movie about Wolverine and Rogue. Yes, they took some story beats the comics had given to Kitty Pride and handed them to Rogue (where they work better, anyway). And you meet a bunch of other people, but it's in passing. It's abundantly clear who the leads of the story really are.

I blame the Batman franchise. In Batman 2, they gave us both Catwoman and the Penguin. Why? Why not just give us one, and really go into some depth with it? But that movie was a hit, so the trend continued. Two bad guys per movie. Plus Robin. And Batgirl. And ... the movies got worse and worse. There's a connection here.

In X2, you could star to see the conrtactual demands showing up: Rebecca Romijn's agent was smart enough to get it into her contract that she gets a scene looking like she looks in real life. Halle Berry gets foregrounded in a pair of scenes. Oh, yeah, and in addition to all the characters we met before, they introduce a slew of new ones and give them a bunch of screen time, too: Pyro and Iceman get a bunch of screen time, which means less for the characters we've grown attached to.

X3 continues the trend. Let's see, we've got an Iceman and Rogue story, a McKellan-Stewart one, Rogue-Wolverine, Wolverine-Pheonix, Storm-running-the-school, and more ... and that's before we get to the main plots (yup, there are even two of them: Phoenix's incredible powers and the battle against the anti-Mutant serum).

Some people compain (correctly) that the ending of X1 is rushed. It's a little on the cheesy side. The special effects aren't as good as the ones in the sequels. But it has something in its core that neither of the sequels have: a fundamental human story which anyone can relate to.

It's about feeling alone, and isolated, not knowing how you fit in. We feel Rogue's pain.

When X2 reaches for similar moments (most notably in the "couldn't you try not being a mutant" scene) they don't work, for two reasons: first, they don't focus on the main characters in the film, so they feel tacked on. And second, because they were tacked on, while it was easy to recognize what the filmmaker was going for ("oh, it's a coming out scene") it was something we saw, rather than felt. We recognize it, but we're seeing it from the outside. It therefore provokes a chuckle of recognition rather than a wince of shared emotion.*

X3 doesn't even try.

If there is a fourth film - and I certainly expect there will be - I hope they narrow the focus again. I know that this gets almost impossible - you're not going to get Hugh Jackman to play a supporting role or take a supporting-character's paycheck - but it sure would make for better movies. Every X-Men comic was not about every X-Man. Every movie shouldn't have to be, either.