Internet Explorer is Perfect
The life cycle of Internet Explorer has inspired a large portion of my career. I love it, and I wouldn't change a thing.
Back around 2000-2004 when I was in college, IE6 dominated the browser market, there wasn't anyone even legitimately close (maybe Netscape, but not really). They were at the top of the mountain with no competition in sight and happily went on auto-pilot for years.
A Company named Mozilla (you know them) started cranking away on a small open source Web browser (eventually called: Firefox) that would ignite the great browser wars and get us to where we are today. It wasn't long before Firefox became a serious threat to IE's market share, souring everyone in the industry to IE's shenanigans.
Internet Explorer is where it is because Microsoft reached the top and got complacent. Watching that happen has always served as a reminder to me to never coast through anything and always try to learn and do more than I think I can handle.
IE is finally catching up to the rest of the pack, but oh man, it was a hard road and a tough lesson to learn.