Any person who considers themselves a die hard fan of the mega-popular, socially conscious Marvel series created by Stan Lee and Jack Kirby in 1963 is likely to already have a sizable collection of comic book issues, live-action movies, animated TV adaptations, and collectible desk ornaments related to the property.
Of course, before you that hit search button, there is something your should keep in mind.
What you probably want to do to really make an impression on them is to find some merchandise inspired by the X-Men that they may not have thought to get for themselves in the first place, such as a decorative item with a modern flair to it or something more on the practical side, even.