Mac OS X's own applications and System Preferences utility provide you with a wealth of settings you can tweak to suit your needs and desires. But they don't give you access to all of their options. Want a standard 2D Dock, for example, instead of the 3D one Apple sets as the default? You can have it, if you know where to look. Now, you could edit the .plist files used to record application and OS settings, but TinkerTool is so much easier to use than that. It presents all these 'hidden' preference settings for Finder, the Dock, specific applications such as Safari and Address Book, and even Snow Leopard-specific items. Download this and set up Mac OS X the way you want it.
Reg Rating 80
More Info and Download Marcel Bresink
Burn doesn't provide too many features that Mac OS X lacks, but it does have the strength of bringing them together into one single place that can become your one-stop shop for optical disc writing. We've used Burn to create operating system install discs from ISO images and for making single-movie DVDs, but it'll do a lot more besides, with sections for Data, Audio and Video discs. It's rock solid and gives you full control over the burning process. We don't burn discs with anything else.
Reg Rating 75
More Info and Download Burn
Free, open-source video transcoder. It just works and has some reasonable default template settings for the non-technically literate (like me).
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.
Perian is a free, open source QuickTime component that adds native support for many popular video formats.
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.
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.