Go to MovieSister.com: They are awesome! I recently discovered this, but they have all movies playing from the theatre for free. It takes awhile to load but they are worth watching a full length movie. You don't have to pay anything. The only trick is getting through their advertisements to watch the movie. You can download free movies online and it doesn't take longer than five minutes to download like most sites. You can easily watch a free movie online using their Bootleg Movies pages.
To watch free movies online, go to Youtube. If the show or movie you want to watch for free is an older one, you are in luck. Most people upload and feature it directly on the Youtube site. The only con to this is that each is only 10 minutes long so you have to keep changing it to the next scenes.
For cheap movies, get Netflix. They send movies right to your mailbox in about 1 day of waiting. Fast service, and best yet there are no late fees. They are only $10 a month. Compared to Hollywood which charges you $4 per rental - I think Netflix is really worth it.
Redbox Rentals. In most grocery stores, they have rental kiosks. You can rent any movie you want from the machine and only pay $1. What a great savings! You must bring it back the following day though and not be late or they will charge you a dollar for being late so make sure you are never late.
Go to the Salvation Army. They have a lot of movies for only $1 to $3 dollars to buy for your home entertainment. Instead of buying movies that are brand new, I buy them used and they are just as good.
For even more cheap movies, try Cinemark Summer Movie Clubhouse. They have movies at a cost of only .50 cents or just $1 dollar. A wide listing of two movie weeks is shown and you are welcome to buy all of them in bulk for only $5.