
VLC
More formally known as the VideoLan Client, VLC is arguably the most format friendly media player you can download. The number of audio and video codecs it supports is phenomenal - both well known and obscure - and you can be sure that if other players shrug their shoulders at a difficult file, VLC will roll up its sleeves and get working. And it'll work with files created beyond the Mac: digital TV data pulled from your set-top box? No problem.

Reg Rating 90
Price Free
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Squared 5 MPEG Streamclip
MPEG Streamclip does for media transcoding what VLC does for playback. It supports dozens of media container formats and codecs, and allows you to convert them from one to the other. And if there's a QuickTime plug-in for other formats, it'll work with them too - and with transcode accelerators like Elgato's Turbo.264 HD - reviewed here. All of which is just what you need to prepares video content for iPod, iPhone or Apple TV playback.

Reg Rating 80
Price Free
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More Info Squared 5
COMMENTS
http://handbrake.fr/
HandBrake
Free, open-source video transcoder. It just works and has some reasonable default template settings for the non-technically literate (like me).
http://wakaba.c3.cx/s/apps/unarchiver.html
The Unarchiver
I haven't had to bother with the Stuffit signup annoyances ever since I discovered "The Unarchiver", which handles at least as many formats (if not more) and is free and open source. The author seems readily available on his site to take bug reports and feature requests too, not that bugs seem too common.
http://perian.org/
Perian
Perian is a free, open source QuickTime component that adds native support for many popular video formats.
http://perian.org/
Perian
This free plug-in gives codec support to QuickTime for all major video formats, including OGG and MKV, as well as subtitle support. While it is a close second to VLC for its formats, the fact that it integrates into QuickTime and therefore exports videos is a huge boon.
Side note: The Squared 5 MPEG Streamclip download link is broken.
http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html
SuperDuper
i found carbon copy cloner to be a bit annoying. superduper is really easy and the paid version allows you to do stuff i have never needed.
