The first Alien by far, The Thing, War of the World’s, Instellar, Starman,
Men in black was stupid and very poor sci fi.
The War of the Worlds (1953). I realize the remake was more true to the book in some aspects, but the first version was amazing, and cemented the genre. It still satnds up, as far as I am concerned.
The special effects, visual and audio, are exceptional. They got the machines about right, and the sound effects were the sort that got recycled by techies in Hollywood: I think the Meson (not Heat) ray effect was the one used in Star Trek for photon torpedoes.
I saw a special on FX in the 1960s, where the Hollywood experts talked about all their favorite sound effects, especially gunshots, and how they got reused in film after film.