Zero Dollar Movies is a website that finds all of the free-to-watch feature-length movies on YouTube, and puts them all in one place for you.
Its catalog goes by year released or language, but interestingly not both. And most of the movies you will see on Zero Dollar Movies are older ones, for which the copyright have expired, but you will also see newer, indie ones as well.
Generally, all of the movies are legitimate, but sometimes you might find one or two movies that you should be paying for on there. Sooner or later YouTube will take them down, though. So you should not expect to be able to use this aggregation engine to aid you in a search for illegal movies.
Know of any other sources like this? Let us know in the comments!