I already picked my British Invaders spaceship so let's move out into the wider universe. It's far too obvious to pick the Millennium Falcon and besides, it breaks down all the time. Likewise the Nostromo from Alien blows up. X-Wing fighters crash in swamps, the Discovery one has a dodgy on-board computer, the Event Horizon goes to hell, and the Enterprise looks like it takes a lot of work to keep it up there.
On the other hand Serenity looks like you really could fix it with a Swiss army knife and a roll of gaffer tape. It's got some style, it's kept in the air by love, and it just wants to do good works. Plus I might be able to afford it or one like it.