If you are up for some classic 1980s cinema, you can watch Arnold Schwarzenegger in the original Terminator or Sylvester Stallone in Over the Top. You won't find any new releases and or any sense of organizational structure, but there are a few gems. The collection of free movies looks a bit like what you might find in a bin of old DVDs at a garage sale. You can see all YouTube's Free to Watch movies here.
While you can rent or buy movies on YouTube, there are more than 300 titles that you can watch for free.