Frankenstein

Frankenstein, the 1931 film directed by James Whale, is one of the big 3 of the old monster movies along with Lugosi's Dracula and The Mummy, and we watch it every year. There are several sequels which we watch less faithfully. I know some prefer Bride of Frankenstein to the original movie, but I'm not one who does. Colin Clive stars as Frankenstein, Boris Karloff as the monster and our favorite Dwight Frye as Dr. Frankenstein's assistant Fritz.

I guess you could consider it one of the big 5 monster movies and include King Kong and Godzilla, which we also watch every year. Oh, and of course Creature from the Black Lagoon.

1000 Misspent Hours says,

More than any other Universal horror film I’ve seen, Frankenstein displays the influence of the German expressionist directors of the silent era, and Whale made a smart move in borrowing from F. W. Murnau’s bag of tricks.

Stomp Tokyo says,

Frankenstein is a classic not only for its age, but more importantly, for the fact that the film stands up to the test of time. A provocative story crafted with the genius of legendary film director James Whale, an extraordinary, pathos-ridden performance by Boris Karloff

Classic-Horror.com says Karloff

adds a depth to what could have simply been a lumbering hulk (and probably would have been in the hands of a different actor). The pathos he inspires in his introductory moments is nearly Shakespearean - and all without a word.

DVD Talk talks about the "greatness of Boris Karloff's pantomime characterization," saying "It's the most subtle, most human and most philosophically profound of the Universal monsters." Rotten Tomatoes gives it a score of 100%.