My first MMO was called Tales of Pirates (originally named Pirate King Online) it was made by Chinese company MOLI in 2007 and published by IGG. It blew me away, it was the first time I could see and interact with so many real people in a video game, I'm a fan of pirate settings so I liked it instantly.
I have very fond memories of it since I got my younger brother and even my dad into it. To this day some of the theme songs give me a strong nostalgia feeling lol.
https://www.youtube.com/watch?v=RQ3f-PdPCfo
The official servers shut down in 2016 but I had stopped playing it quite a bit before that.