I'm not a big fan of top coats.. I'm too lazy, as I said reviewing Essie Matte About You. I really like the ones that gives particular effects though, as this Holographic by China Glaze.
It has a microglitter slightly colored finish, that changes like the base nail polish color.
Here you can see the swatches:
In this first picture you can see the difference on the nail polish (which is Catrice London Forecast Weather) with and without the top coat.
Here instead you can see the complete nailart, with a Konad stamp with Special Nailpolish in Black.