King Kong extended version which is over 3 hours long. And also LOTR smash pack or w/e it's called. All the movies put together which i actually took the time to watch only one time. Also the first time i watched LOTR.
Longest movie ever watched, other than Lord of the Rings (which doesn't count cause it's in three different parts), It would be a tie between Gangs of New York, And Master and Commander.
Longest movie Doesn't necessarily have to be the "longest movie" to feel like the longest movie...know what I'm getting at? Try watching Little Women for 2 hours. I got dragged into it by force, and I feel bad inside because it was only 2 hours long but felt like 5 hours. The only thing that made that movie better was because the guy in front of me was criticizing it, so it was funny.