I guess we'll go with the long version.
I was in my first semester of college. I had put off studying for my chemistry exam, so in true college fashion I decided to try a Monster energy drink for the first (and last) time to help me stay up all night to study. I had no caffeine tolerance at ALL at the time, so it blasted me awake and made me jittery to the point that I felt like I was on drugs. I got through my studying, and was still wide awake at 5pm the following day to take the exam. I took the exam (and conquered it), got back to my dorm room, was mentally exhausted and wanted to crash, but I couldn't. I was still physically very very awake and sleep was not going to happen.
I started killing time online, tried to watch an episode of some show but just could not enjoy it, and after lots of fairy mindless clicking, I found myself on Omegle.com around 11pm. It's a site where it puts you in a one-on-one anonymous text-only conversation (instant messenger style) with another user of the site. At the time, it was fun to mess around on there and troll/talk to random people. (Nowadays, it still exists, but it's a bunch of spam, horny people, fake hot singles in your area, etc. Back then it was still interesting and had real people.) So I had a few short conversations with people, nothing too terribly interesting, so I decided to start opening conversations with quotes from The Simpsons, for fun and to sniff out Simpsons fans.
"Don't you hate carpet stores that charge extra for the underpadding?" was the first sentence I ever said to her. We went back and forth, being increasingly very silly and fully expecting the other to disconnect and move on. Eventually that collapsed under its own weight, we became instant friends, and had a real conversation that lasted an hour or two. We then established a more permanent form of communication via email, Yahoo messenger, and Facebook, as we both realized we wanted to be more than "single-serving" friends. So we became real friends. She was in Arizona; I was in Illinois.
She quickly became one of my closest friends and we helped each other through tough times. Just under two years later, I went to a concert in Chicago, and got back home around 1am and instead of going to sleep like a sane person, I jumped online to talk to her. One thing led to another, and we expressed our romantic feelings for each other.
Three weeks later I hop on a plane to Phoenix. It was a very surreal experience actually being on that plane, knowing I was actually going to finally see her in person. I got out into the airport and out to the curb. Somehow I had it in my mind that I was waiting for a black Kia. I stood there, looking down the mass of cars, scanning for a black Kia as the cars all went by. Then right in front of my face, a BLUE Kia loudly honks its horn at me and I whipped my head around and made eye contact with her for the first time. We went back to her place, and her sister's dog barked in my face for half an hour. We watched Hot Fuzz and played Apples to Apples with her sister and her friends. She and I shared a bed that night.
Five months later, we bought our first house together (at 19 and 20), and she moved across the country.
We have lived together for almost three years now. Everything is wonderful. Life is good.
"We met online but it wasn't a dating site." is usually the short version we tell people.