DOS 3.3 is what I started with in 1988. I got a free copy of Quicken V2 from the Intuit driver (I was with Fedex on the mid-peninsula at the time).
5-1/4” floppies were a big part of my life for a time.
It’s interesting to me that Windows Vista and Windows 8.0 didn’t stay long as No. 1. Probably because they were both duds.