i agree with many points made in this thread.
i do agree that, in regards to these being comic book adaptations, x-men is the best of the trilogy. perhaps it is because it doesn't take from a specific story, and it's a rather basic x-men vs. brotherhood storyline, it makes less changes to the source material.
x2 obviously begins to make more changes from the source material, and x-men: the last stand is obviously the worst in terms of being an adaptation.
in terms of being a well made movie, x2 is probably the best, but it isn't without flaw. after seeing the movie a bazillion times, the climax is beginning to become a bit more boring to me. the x-men split up, and except for a poorly choreographed wolverine vs. lady deathstrike battle, there's really no action. x-men at least has an action filled climax, even if i think the rest of the movie isn't as good as x2. x-men: the last stand is the complete opposite of x-men. x-men is little action, but big on character development. x-men: the last stand is little on character development, but big on character. i think that both attributes are equally important, but in the end, i prefer x-men: the last stand over x-men because i think it has a much more exciting story.
in terms of remaining consistant with the previous films, i believe that both sequels do a good job of that. i don't have any problems with the consistancy of the sequels.
in the end, i don't know which i prefer between x2 and x-men: the last stand. x2 does less wrong, but when x-men: the last stand is working correctly, i believe that it is the best of the series. x-men: the last stand is to me, at the same time, the best of the trilogy, and the worst of the trilogy. in the end, i rate it higher than x-men, but it's hard to rate it compared to x2. at times i want to say x2 is the better movie, but there are definately many elements to x-men: the last stand that i prefer to x2, so it's a tough call for me.
at the end of the day, i love all 3 movies, and i'm very happy with the x-men trilogy that we got.