Director: Bryan Singer
Until Logan came out a few years back, I'd argue X2: X-Men United (2003) was the *best* X-Men movie, which may be a sign of how quickly I felt the franchise devolved, but it does wonders to build on the original, expand the world, mine the premise for narrative gold, and set us up for both continuing X-Men films and potential Wolverine spin-offs.
Jamie was asking me if the movie was based on stuff from the comics, and while I could definitively say it was, I also don't know exactly when and who wrote them. I didn't get to Uncanny X-Men until around issue 170, with the kind of third incarnation of the X-Men, but - and here's my argument to the Big 2 why you just go ahead and keep on your Chris Claremonts as long as you can - all of the stuff from those stories 50-100 issues prior still had impact in what I was reading years after the fact. The writer knew and remembered the important stuff, and it was woven into the character's lives and informed how they behaved and thought about things. *