SMPlayer is a trimmed-down media player that uses the playback engine of MPlayer and includes built-in codecs. 64-Bit also available.
It will remember the settings of all the files you play; this allows you to leave, and the movie will resume precisely at the spot where you left it when you're ready to start watching again - no searching. You have the most popular formats and codecs supported, including AVI, mp4, MKV, MPEG, MOV, DivX, H.264, and more. A full list can be found on the author's site.
SMPlayer also includes YouTube support, numerous video and audio filters, a complete preference dialog, and a thumbnail generator. There is also a video equalizer, multi-speed playback, audio and subtitles delay adjustment, the ability to search and download subtitles from opensubtitles.org, and multiple skins to choose from if you want to change the look.