Boring with the default Alt-Tab window switcher? In Ubuntu 18.04 and higher, you can easily enable Windows style flip 3D effect via Coverflow Alt-Tab extension in the default Gnome desktop.
Since Ubuntu 18.04 has merged Gnome Shell extensions into Ubuntu Software, simply search for and install coverflow alt tab in Ubuntu Software:
Then you can get into the settings page either via the install page or Gnome Tweaks.
Finally press Alt+Tab on keyboard to see the effect: