Looks-wise, the Athena, then the Artemis DH, then the Apollo.
Flying-wise, the Serapis, then the Horus, then the Perseus.
Shooter-wise, the Ares, then the Tauret, then the Herc 2.
Best bomber = Artemis DH and Sekhmet.
Overall, though, it has to be the Mara. Fast, hard, and huge missile bays. If only you could take Prometheus and Maxims... I suppose a tbl fiddle is in order...