I’ve had lots of good ones, as I seem to be a champion burper. Even without drinking soda. I can burp on command, by gulping in air bubbles down my throat. It’s very weird. As a teen, I was kinda proud of it, and won many a burp-off against guys who were chugging sodas. As an adult, I try to always burp quietly around others, and sheepishly say, “Excuse me!”
I think the longest one I ever had was when I trained myself to make my burps last long enough to blow through the whole alphabet in one burp. Classy, huh? :D