This is a cute question, I don't remember which one it was but I would have to say, the one that throw up on the Macbook Pro! That was a classic video.
I like Wicket
The name is cool and the dog itself is cool too...
Not that Pixie is worse or anything, but I think I would pick Wicket as the Geekiest dog Chris have... :D
Have to go with Pixie---the dog peed in place on the floor, wearing her Princess Leia costume (halloween). Only a true geek would get spooked enough to and pee in place.