The best epoxy to use depends on the project. 

TotalBoat Traditional 5:1 Marine Epoxy Resin has an optimized viscosity for wetting out fiberglass cloth and cures to become a more rigid plastic with higher tensile strength, compressive strength, and modulus. It is available with slow or fast hardeners, allowing it to be used under cooler conditions, and is designed only for thin-film applications. This product cures with an amine blush on the surface and can have a slight amber color once cured. 

TotalBoat Clear High Performance Epoxy has an easier 2:1 mix ratio to dispense, a slightly lower initial mixed viscosity, and cures to a clear, high-gloss finish with no amine blush. This epoxy system comes with a slow, medium, or fast hardener and can be applied up to 1/4 inch thick. This epoxy system still has excellent tensile, compressive, and modulus performance characteristics.