If you're asking people to list their 10 favorite sci-fi space ships, you're really just challenging them to list 10 that they can remember.
I really don't care to rank them, so I ordered them alphabetically...
Battlestar (BSG)
Corona (Katsuhiro Otomo: Memories)
USSC Discovery 1 (XD-1) (2001: A Space Odyssey)
Enterprise NCC-1701-A (Star Trek)
Enterprise NCC-1701-D (Star Trek)
Event Horizon (from the film of the same title)
Lewis and Clark (Event Horizon)
Millenium Falcon (Star Wars)
Narada (Star Trek)
Nebuchadnezzar (The Matrix) - not really a spaceship
Nostromo (Alien)
Prometheus (from the film of the same title)
USS Reliant (Star Trek)
Slave I (Star Wars)
USS Voyager NCC-74656 (Star Trek)
[edit]
Added USS Reliant because I thought of it several times while writing that list and still left it out somehow.