Lotus 1-2-3 is 30 years old Jan 29 2013
While VisiCalc concentrated on just being able to do spreadsheets at all, Lotus 1-2-3 went to the next level and addressed the final printed output much better, with more number formats, variable column widths, long labels, and that very-hard-to-do-by-hand graphing. And it did all of this with greater speed than anything else. Speed and fluid operations matters, as the Palm Pilot later showed (with its instant page turning in response to taps), and then the Apple iOS products showed after that.
The code itself stood the test of time and for years beat out most other products running on the hardware for which it was designed. It wasn't until a platform switch occurred (GUI) that the torch was passed to the next dominant spreadsheet, Excel.
The team Mitch assembled to get the "full" product (including documentation, sales, etc.) out the door had some of the best positioned and most experienced (with personal computing) people in the world. He also worked with one of the most tied-in to the personal computing business venture capitalist, Ben Rosen. A dream team at the time and in hindsight.
Also, wow, this Lotus 1-2-3 promotional video from 1983 is amazing:
My dad had a copy of the first version of 1-2-3...we both used the hell out of it for a long time. (via @joeljohnson)