If you are looking to bring your SharePoint form design to the next level you should seriously consider Nintex Forms. Nintex provides an easy to use Form designer that will provide increased functionality over default out of the box SharePoint forms. Easy to use and powerful, Nintex is pretty darn good!
If you are looking to build custom workflows on the SharePoint platform consider Nintex Workflow as one of the top solutions available. Nintex provides a powerful, easy to use workflow designer that provides the power of Visual Studio with the ease of use of PowerPoint!