So many to choose from, but I think mine was AmiPro just after Lotus acquired it. I was a 1-2-3 guy, so didn’t want to switch to excel/word, etc. AmiPro was Lotus’ word processor. I thought it was excellent. It had an easter egg that would start a tiny game of Mastermind. Depending on your score it would compare your intelligence to some popular person. I think winning made you Einstein but more memorably, losing made you Al Bundy.