I really liked Windows XP.

Hard to believe it first came out 17 years ago.

https://en.wikipedia.org/wiki/Windows_XP

Developer	Microsoft
Source model	Closed-source Source-available (through Shared Source Initiative)[1]
Released to manufacturing	August 24, 2001; 17 years ago[2]
General availability	October 25, 2001; 17 years ago[2]
Latest release	Service Pack 3 (5.1.2600) / April 21, 2008; 10 years ago[3]