There are a number of movies I'd put in this category.
Three, right off the top of my head:
* Star Wars
* Das Boot
Each one lived up to the type of movie it portrayed and excelled.
@lindalou1963, I agree with you about "The Green Mile." I'd also say that "Shawshank Redemption" was right up there, too. And yes, Titanic, too.
I have many favorites that wouldn't make the "flawless" category. Most of the Star Wars series, half of the Star Trek series of movies and even the classic, "Forbidden Planet" was flawed (dialog was awful in places).