In no particular order...
Indiana Jones Trilogy
Die Hard Trilogy
All 5 (soon to be 6) Star Wars
Star Trek II: The Wrath of Khan
Star Trek III: The Search for Spock
Star Trek IV: The Voyage Home
Star Trek VI: The Undiscovered Country
Star Trek: Generations
Star Trek: First Contact
(the other Star Trek movies are ok, but not in the class of the ones above, IMHO)
South Park: Bigger, Longer and Uncut
Shrek
Titanic
The Fugitive
Robin Hood: Prince of Thieves
The Princess Bride
X-Men (still haven't seen the second one, dangit)
Midway
A Few Good Men
Mission Impossible
Mission Impossible II
Independence Day (completely unbelievable but still fun)
Robocop (but only the first, they should've stopped there)
The Craft
The Exorcist (and as scary as the movie is, read the book.
)
The Long Green Mile
The Shawshank Redemption
Men in Black (again, the sequel sucked)
Enemy of the State
All of the Dirty Harry movies
Absolute Power
Debbie Does Dal...oh wait, wrong list