-Batman Begins. I was blown away by it in the theater. I bought the DVD as soon as it came out, watched it immediately, and loved it again. After that, I went a fairly long time without watching it until it started being shown on cable. After watching it on cable (the whole thing or parts) with some frequency, it kind of lost its luster. It's still a good movie, but after the coolness and newness wore off, I started being more bothered by some of its shortcomings (exposition, fight scenes, etc.). This effect was exacerbated somewhat by my underwhelmed reaction to The Dark Knight (I still like it too though).
-V For Vendetta. I loved the book and movie in high school and early college. After I got older, more mature, and more well versed in movies, the film's flaws became more apparent and its themes seemed much more toned down than I originally thought. It's still a pretty good and entertaining movie; just not something spectacular.
-Equilibrium. Once the novelty of Gun Kata wore off, I couldn't get over how impractical it seemed, even in the context of the movie. And the dystopian setting seemed way less smart when I sat down and thought about how similar it is to 1984, Brave New World, and Fahrenheit 451. The one thing that didn't lose appeal for me is the action sequences; they're elaborate for such a low-budget movie.