[saltcured]

If we count email, I still use an address from my employer that was established on my first day in 1997. I lost my college accounts around then, though a student group one lasted longer than official ones. Since email was also used with USENET, I didn't have any other online, public-at-large accounts until instant messaging invaded work a few years later. So I think I had AOL (AIM) and Microsoft (MSN) first, but haven't kept them active.

Close in there would be online commerce. I don't have detailed records, but probably started using Dell and Amazon quite early in the original dot-com era. Probably also B&H Photo Video and Crutchfield, since these were businesses I already knew from the mail-based catalog era.

I think I also had an online account with my bank by around the same time I started my job, though it took me a couple more years to wean myself off writing paper checks and primarily using bill pay.