The HK Girl Top Coat is absolutely, hands-down, the best top coat I have ever used. It dries extremely fast, hardens, doesn't shrink, seals in color, and blasts your nails with shine.
I have a couple pictures to demonstrate. Go to their website and buy some today. Seriously.
I put on two very thick coats of Essie Silken Cord lacquer and only waited about 3 minutes before applying HK Girl Top Coat. It was dry within 5 minutes. Rock solid dry.