ING Rollover Wizard
Right out of college, I was tasked with using an Adobe form program that crashed constantly, that I didn't know how to use until I started working with it, and with no one support except my manager and the guys doing the back end.
It did all kinds of wonderful things, but mainly you'd fill it in and wouldn't have to re-fill in those bits in later sections, and it would serve you up specific forms you could fill out based on your input.