I'm not just going to give a list of 25 best movies. To me, movies have, in a way, opened my view of the world and my own life. Over the years, there are movies that have closed chapters in my life.
There are directors whose movies have expanded my view of the world - Stanley Kubrick for one, Robert Downey, Sr. for another
I'll start with a Kubrick movie. 2001, A Space Odyssey. I grew up in in the 50's in a small town in the bible belt of central TX. I am the son of a Baptist deacon, and had a "Leave it to Beaver"-like childhood. My parents didn't drink or abuse my brothers or me in any way. My mom was a homemaker most of my childhood, and when I would come home from school, there was always fresh baked dessert of some sort. My dad would coach my little league baseball team. You get the picture. I say all this because I led a very sheltered life as a child and teenager. Movies were a way of broadening my world. Anyway, I digress.
In the 50's and 60's, movies were shown in large movie theaters with minimal technology, and mostly consisted of westerns and 1950's Sci-fi (Them, The Thing from Outer Space, etc). I was always enamored with planes, astronauts, space travel, etc. One day on television, they mentioned the movie 2001, A Space Odyssey. In a town about 30 minutes away was one of the new (for 1968) movie theaters with a wide curved screen and stereo sound. I asked to go there for my birthday and see 2001. It was an experience I will never forget - the quality of the special effects, the use of music, the overall quality of the movie - the way it looked - the way it made me feel - I was hooked. My mind had been blown. It was love at first sight.
In the transition from small town boy to big college, "A Clockwork Orange" came out. Again, Kubrick blew my mind. The stylized violence, the use of music - to this day, Beethoven's 9th is one of my favorite pieces of classical music. The use of music played by a synthesizer - Wendy Carlos nee Walter Carlos - the intermixing of show tunes with classical - "Singin' in the rain", "I want to marry a Lighthouse Keeper","Pomp and Circumstance", "The William Tell Overture" and Beethoven's 9th all in the same movie. It made my head explode.
Then one year in college, I had a roommate who was kind of an "out there" intellectual type. He was a zoology grad student working on his PhD and was into jazz and movies. He introduced me to some of the movies of Robert Downey, Sr. - specifically "Greaser's Palace" and "Putney Swope". Greaser's Palace is still one of my favorite movies. It is based on the bible if the characters were set in the old west. It's too hard to explain, but it is one of the weirdest movies I have ever seen where the story line still made sense.
He also introduced me to older movies - Sabrina, North by Northwest, Casablanca, African Queen, Treasure of Sierra Madre, etc. Of that group, if I am flipping through the channels on my TV and see North by Northwest, I'm stuck. It is great movie making. He also got me interested in knowing the directors - looking for certain directors - Alfred Hitchcock, John Huston, Frank Capra, Billy Wilder, etc.
He also got me interested in foreign films - French, Czech, British, etc. I think of the original Tall Blond Man movie. I remember it was hilarious. The "Pink Panther" movies with Peter Sellers are incredibly funny. I got interested in Italian directors - Fellini (8-1/2, Amarcord), Lena Wertmuller (The Seduction of Mimi, Swept Away), Paolo Pasolino (Decameron). There were some very sexy French movies from that time as well - Betty Blue comes to mind. I also think several of the Simon Pegg, Nick Frost movies are good - Shaun of the Dead, Hot Fuzz. I really like "Paul" as well. Speaking of Nick Frost - if you haven't seen "Kinky Boots" you are missing a very entertaining movie. I also like "Cuban Fever", but mainly for the music.
Then things got serious in America - "The Godfather","Star Wars","The French Connection", "The Conversation", "Jaws", "Close Encounters of the Third Kind", "Alien". New directors were popping up, with new ways of making movies - Steven Spielberg, Francis Ford Coppola, Ridley Scott all appeared about this time.
I even enjoy the teen movies from that era - the John Hughes movies (Sixteen candles, Pretty in Pink, etc) Ivan Reitman is another director that I was interested in. I think he directed "Ghostbusters". I was also interested in other comedic directors - Woody Allen (Sleeper, Love and Death, Take the Money and Run, etc), Mel Brooks (Blazing Saddles, Young Frankenstein), and one of my all time favorites - Monty Python movies (I think Terry Gilliam directed them) - The Holy Grail (She's a witch), Life of Brian.
I haven't even touched on war movies - The Longest Day, 633 Squadron (used as the basis for the death star scene in Star Wars), 12 O'clock High, The Bridge over the River Kwai, The Guns of Navarone, The Green Berets, They were Soldiers, Run Silent, Run Deep, The Great Escape, Stalag 13.
Now we get to more modern movies - ones where the technology is well-developed. Iron Man (the original one), Captain America (the original), the new Star Wars franchise (JJ Abrams - whew!!!), Guardians of the Galaxy, Avatar (James Cameron is kind of hit or miss with me - Titanic blew chunks, but Avatar and the Terminator were groundbreaking), The LOTR and Hobbit movies (Smaug is the best dragon I have seen in any movie). I think Peter Jackson's movies are about as close to perfect movie-making as I've ever seen. I think he is Stanley Kubrick reincarnated. (they actually kind of look alike). There are smaller movies as well, such as "The 100 foot Journey" and "The Grand Budapest Hotel" that I think are excellent.
Geez, I just realized I haven't even touched on Rob Reiner. One of my all time favorite movies - one that I would take to a desert island - is "The Princess Bride" I also really like "Stand by Me", and "This is Spinal Tap" has to be one of the funniest movies of all time.
I also think Ron Howard is a very talented film maker - Apollo 13 is a real tight asshole movie even though you know the ending. I love auto racing and F1, so I thought "Rush" was really good as well.
Sorry for being so verbose, but, for me, films are more than just entertainment. I am fascinated by the process. Essentially starting from a blank piece of paper (film) and producing a visual and auditory story that entertains, moves, and challenges the audience is real magic.