My fiance and I literally make groan-worthy puns at each other daily, yet somehow I can't think of an "us" wedding hashtag. I want to use it for the URL for our website too yet I can't come up with it!
Last name will be Geerling and his name is Sam. We're having a Celtic/Viking themed ceremony + reception will have geeky references as well. We love Star Wars, Jurassic Park, Harry Potter etc. Very intellectual as well -- he proposed at our hometown's science center.
A sci-fi couple we identify with is Wash and Zoe from Firefly. No idea if that helps. He's a Slytherin and I'm a Ravenclaw. LOL. Help!