I would go with Dahak. What is a "Dahak", you might ask? Well...
It's the moon. Or rather, a "spaceship" (by loose definition, because hey, MOON!) that is the size of the moon (in fact it was disguised as the moon for a couple thousand years in the parent novels) that is also fully sentient (and quite a nice fellow to boot).
On the offensive side it has FTL capability, its own fleet of warships with an entire factory capable of churning out even more ships, weaponry that can blow anything short of a attacking fleet numbering in the millions out of space and it has a nigh-infinite supply of gravitron warheads that can literally tear apart planets (eat your heart out, Death Star!).
But the best part? It also has faculties capable of supporting a crew of several million and it even has a mansion-sized captain's cabin with all the luxuries one could imagine plus several recreational centers that are literally giant parks the size of a Central Park, and it has an entire human augmentation suite that allows people to enhance themselves to the point of becoming supermen with several hundred year lifespans.
So yeah, I would probably just take my sweet moonship, take a few million of the most reasonable people on the planet with me and I would just sail the stars for discovery and fun.