I took a punt of Gravity Forms, being somewhat unhappy with other form creation plugins - they worked but for clients that need complex forms, the hours would mount up and the profit would evaporate quickly.
With Gravity Forms, complex forms come together quickly and easily. Now i don't wince when a form is requested, i just get on with it. Forms went from the most time consuming part of my work - to the easiest, stress free process.
Conditional Logic didn't seem interesting or needed, now it is a feature i could not do without. Forms made easy.