I'm redirecting to my own guide to watch movies for free, the comments also have great additional recs, specially https://rarefilmm.com/ and https://www.solidaritycinema.com/
Among all of these options I highly reccomend exploring Buster Keaton's filmography featured in Cinema Antiqua youtube channel (quite good quality for 1920's movies for free), as always it's fun to see the stunt king in action.
Among the Internet Archive I've enjoyed watching to great japanese animation like Roujin Z and NeoTokyo