I have found that it is. The only exception is anything Norton because it takes using their special Removal Tool to be throughly removed from a system.
In the last comparison test of free uninstallers I saw, which was over 2 years ago in the German computer mag CHIP, Revo came first and CCleaner fourth. But matters don’t stay static in the field, so I can’t tell you what the situation is today.
However, I can tell you that none of the uninstallers that come “after the event” can do a thorough job without leaving any traces behind, while their advanced setting also entails some risks of deleting other stuff.
For a complete uninstall, you need a premium product, which records all registry changes during installation of an app, so that it can totally reverse them later in a safe manner. It may even re-install the app, if you decide you needed it after all. Right now, I only remember Ashampoo Uninstaller as one example of such a program, there are others, none of them free, as far as I know.