Full Screen Player (OS X)

Full Screen Player is a full-screen QuickTime movie player. You can use the Finder to organize your movie files, make aliases of movies into a folder as a playlist, and drag and drop movie files or folders onto the movie window of Full Screen Player to watch the show.

You can also change various options while watching movies, including three different screen sizes; separate bass and treble controls; and fast-forward, rewind, and slow-motion controls.
Version 1.1 added different playing modes and a controls menu that lets you change movie size and playing mode. It's also easier to switch to other applications when in Full Screen presentation mode. The menu bar and the Dock will appear when you move the mouse. This version adds a new Aspect Ratio menu. You can choose to use the default aspect ratio of the movie, or force it to 4:3 or 16:9. This version adds a few menu items: Next Movie, Previous Movie, Volume Up, Volume Down, Mute.