I have a thing for old films, whether they be comedy, cowboy or campy horror flicks. While the newer stuff can be streamed from NetFlix, there is a great source for downloading old films that are now considered public domain. Internet Archive has more than just movies, but that's all I'm covering today. You can download or stream everything from early silent films to early 50's TV shows to horror films from the mid-80's. I enjoy just browsing to see what has been added recently.
You generally have your choice of formats, such as Ogg Video, MPEG4 and MPEG2, even animated GIF. Search by title or genre, actor or producer. They also list the top 10 downloads of all time and last week. Two films that always seem to be in those top 10 lists are "Night of the Living Dead" and "Reefer Madness." I will admit that the last film I downloaded from this site was the last Laurel & Hardy film, Utopia (1951). The quality of most of the films is not great, but I still enjoy watching them, and you can't argue with the price.
One other site for the movie buffs out there — Movie Dubbers. This site has a huge list of films with the listings of who sang for which actor/actress, who played piano/trumpet/whatever, or who danced. In the case of "Death to Smoochy" it was Elvis Stojko who skated for Robin Williams.