symbolics.com was the first name registered. If it wasn't first, I'd be interested to hear which domain was. I had to write a paper about it once upon a long time ago, and since I didn't get a big F, I'm assuming the multiple sources that cited it as being first, weren't lying.
http://www.zakon.org/robert/internet/timeline/
This wasn't one of them, but it's pretty good, and he cites additional references at the bottom.