I really dug X-Men, if for no other reason than the fact that Singer struck a just about perfect balance between creating a "serious" treatment of the comic (as best as could be expected) and creating something for the fans.The complaints that I've heard (here, and elsewhere) that say that it bucked the comic continutity too much are valid, but a bit narrow-minded IMHO. To require that the movie be a rehashing of what's already come in the comics would have alienated the general public. Let's face it: comics fans alone would not have made X-Men enough of a success to warrant a sequel (or two). If this means a bit of retooling in the interest of making a solid story, I don't have any problem with that, as long as the characters aren't dramatically altered.
Most of the changes were insignificant at best, neccessary at worst. In the end, I think it all made for a good introduction to the characters, and an entertaining story. Certainly, some changes/additions would have been nice, but Singer produced a quality movie with all the limitations imposed upon its production.
My Ũ.03 - (inflation)
Stymie
Not knowing a lot of the background of the X-Men ie not exposed to a lot of the comics, plus the fact that there was hardly any hype for it down here, I had an no unrealistic expectation. All this contributed to the fact that I quite enjoyed it. I thought it was a good introduction anyway and am slightly looking forward to the sequels. 
