I'd have one that would actually work properly in real space, rather than these hacked-together, handwaved abominations which everybody else seems to pick. [http://www.escapistmagazine.com/forums/read/18.100198#1554585]
With that in mind, I suppose it would have to be Discovery One from 2001: A Space Odyssey, because it's one of the only fictional spacecraft that actually conforms to real rules of spacecraft design. None of this handwaving nonsense (well, apart from stylistic elimination of the massive cooling fins that it should have, but considering how far ahead of the realism curve it is, I'll give it that one exception for free).
Things like the Death Star are clearly stupid (have you ever wondered why they had to have a whole load of exhaust ports?), and most of your choices would fight like actual naval ships, as in, inappropriately for exoatmospheric conditions.