What is the best advanced webform add-on?

We are looking for a solution that provides a better design-feel and more capabilities that Infusionsoft’s standard webforms.

Does anyone have any recommendations? I’ve looked at Jotform and through Infusionsoft’s apps, Success Forms and Elegant Forms.

Any advice would be appreciated!

If you are working in a Wordpress environment, I love using Gravity Forms and integrating with Infusionsoft that way.
Otherwise, Jotform is a pretty popular alternative.