I logged into GameFAQs the other day, and noticed I'd created my account in 1999.
After some poking around my password manager, the only other account I could find still "in use" was an eBay account that I also created in 1999.
I felt a small sense of wonder at having still-functional accounts that are 25 years old.
What are your oldest accounts? What do they still do for you?
My favorite account I used to have was username@ibm.net, back when they dabbled in consumer ISPs (unlimited dialup!). Sadly, they discontinued that service after a while.
I used to have really old Steam, Amazon, Slashdot, Facebook, and reddit accounts too, but deleted them all for various reasons.