Nothing beats Leverage:
http://www.marinecleanusa.com/
http://www.trickmarine.net/productde...=1381&incat=68
A great alternative to Leverage is Race Glaze:
http://www.speedwakestore.com/produc...cat=258&page=1 The guy /company that painted my boat (Mitcher T) told me this is his favorite. Very easy to use polish, and leaves a great shine and UV skin to protect the finish as well.
Just be sure NOT to use anything with Carnauba in it - as it will yellow over time and actually accelerates oxidation of gel coat. Gel coat needs to "breathe", so-to-speak - and a polish made specifically for gel will allow it to do so - keeping the finish looking new.