Contrary to popular belief, uninstalling applications on a Mac doesn't just reside in trashing a file. You often need to check into the library and also remove application support and cache files. An uninstaller like AppCleaner will make sure all unwanted files are removed.

Appcleaner features simple drop and uninstall, like other uninstallers but also lets you browse through your programs, divided in applications widgets and others. This last one I really like as it shows all your plugins and components, which you normally have to go digging for in your library. Note that it will also take care of caches and receipts.

Appcleaner includes a search function to find applications faster, and I liked having the SmartDelete feature which will detect and trash related items. You can protect launched and default apps and 3D transitions and choose other ones you don't want to delete.

The only drawback in my opinion is the uninstall process, where you first have to search for the program, then uninstall it.

Apart from this minor issue, I think Appcleaner is an excellent uninstaller with both protection and smart removal, and surprisingly it's free! A must.