I'm going to divide this into two parts - movies I want to see that people have listed (because I can't be arsed to list every single movie I ever want to see), and my 2 cents on what I think of movies that I've seen that people might want to consider). So, on that note:
Part 1
-Schindler's List
-Full Metal Jacket (I've seen some of this film, wouldn't mind seeing the rest)
-Dune (I actually have this on DVD, just haven't found time to watch it. Also helps that I love the novel it's based on, though I haven't read all of said novel)
-Gone with the Wind
-Superman (original) (in that I liked MoS, so I might as well see how great this version is)
-Godfather Trilogy (might as well see all three)
-The Thing
Part 2
-Spirited Away
See this. Please see this. The amount of creativity it displays in its visuals alone is worth the price of admission
-Citizen Kane
I reccomend this film. It's a bit slow compared to modern films, but I feel it's a movie that people should see if only to get a greater appreciation of the medium, how it incorporates elements of both theatre and film into its cinamatography. I actually saw it for the first time when I tutored a student in English, and I loved it)
-2001: A Space Odyssey
I really don't like this film. It's not that I don't "get it" - I do. But while I absolutely adore the novel version, the film is just too slow for me. I can enjoy slow films (Citizen Kane, to recently seeing Rams), but this film takes the cake. But that said, I think it's worth seeing this film, if only because of its historical context in the medium, how it's perhaps the first "serious" sci-fi film. Also, as slow as it is, it's a very intelligent film, how it tells (by my interpretation) the story of human evolution, with its protagonist being an abstract (humanity itself). Just be prepared for a film where dialogue doesn't occur for about 25 mintutes. Controversy time, but I actually enjoy the film "2010" more.
-GoldenEye
My third favorite Bond movie, my favorite Bronsan Bond movie, and actually the first Bond movie I saw. Give this one a watch.
-Grand Budapest Hotel
This is a mixed bag for me, but I'd reccomend it. It's got a quirky, off-beat style that works, but I have to say, this movie feels exhausting at times, like it uses that style so much it loses impact. But there's still fun to be had.
-Casablanca
This is actually my aunt's favorite movie of all time. As for myself...it's okay. It's good, but I don't really see why it's considered a cinematic masterpiece. There's still fun to be had.
-To Kill a Mockingbird
One of the rare film adaptations that surpasses the book it was based on. The court sequence is easily the highest point in the film, but the rest of it does a good job of highlighting life in the 1930s of the "Deep South," and it follows the themes of the book excellently (e.g. the 'innocence of childhood'). If anything, listen to Atticus's closing speech on YouTube. It outright deserves it.
-Galaxy Quest
If you like comedies, you'll like this movie. If you're invested in nerd culture, you'll love this movie. If you like Star Trek, you'll either adore this movie, or go on a rampage by being 'insulted.'
-Lawrence of Arabia
It's been ages since I've seen this film, and I saw it over a number of sessions due to how long it is. But yes, I reccomend it.
-Apocalypse Now
This is a mixed one for me. On one hand, I do think it's a good film. However, it's not a film I particuarly enjoy watching due to how long it is. Also, in the edition I saw, there's a lot I felt was superfluous, such as the French plantation sequence. It also didn't help that I watched and studied this film alongside Heart of Darkness, which I loathed. I do reccomend watching it, but no promises as to whether you'll like it. But at the least, I do consider it better than the book that inspired it.
-Monty Python and the Holy Grail
Not a fan. I just didn't laugh that much, found the use of the real-life setting (e.g. the historian) out of place, the animated sequences too weird, and...yeah. I prefer Life of Brian, and even that I don't consider to be all that great. Intelligent in some ways, but not "great," per se. If anything, I enjoyed Holy Flying Circus more.
-The Lord of the Rings
Favorite movies of all time, love the extended additions, see it see it SEE ITTTT!
(But yeah, see it.)