I always liked Flash Gordon's because of the exhaust pipes. Looks like a six cylinder. Then again The Heart of Gold is pretty cool because of the Infinite Improbability Drive. But the all time best ship is the Dragon Zephyr, from the book The Void Captain's Tale. It's piloted by a woman by making "Hyper Jumps" through cosmic orgasms. (No picture available.)
I would pick THE ORIGINAL ENTERPRISE from Star Trek! (NCC-1701) EDIT: I found an awesome star trek site and registered straight away!! http://www.trekbbs.com/index.php?styleid=1
The Enterprise from "Next Generation." Wouldn't it be cool to have a holo-deck? You could go to any place or time on your day off?
The Millennium Falcon (with the round dish, not that stupid square one). I can't imagine a cooler ship in any galaxy.