They are all very different, so that is hard to answer. Generally for each of the games you'll find somebody who will tell you that it is the "amazing one".
Personally I love monsters as a great tower defense game that shines in coop (but there are quirks to the style such as trial and error over long levels).
Eden is a zen like experience. Not my cup of tea, but I can see others loving it.
Shooter didn't really do it for me. It is very much a retro experience which played better on console, but you can find plenty of other oldschool games on steam.