I've worked in a cube. I've had my own office. I've shared an office with one other person in a variety of desk arrangements. I currently share a large office with three other people (might as well be an open plan).
I'd probably rank the cube second, with sharing an office with one other person as the best (with desks arranged so both our backs are to the wall).
Open offices are terrible, terrible things. Next time I interview, I'm going to make sure to ask what their office arrangements are, so I can avoid that situation.