For nice widget animations you can install a GTK engine/theme. There is a deluge of GTK themes you can choose from if that is your thing.

There are many themes inspired on macOS if you are aiming for that kind of look.

http://reddit.com/r/unixporn has a lot of that stuff. You can just go and grab someone else's configuration and apply it to your system.

If you are aiming for window effects with no regards for performance, try Compiz. You can add as many window effects as you want.