Sword of Indomitable Righteousness
Scepter of Unbearable Pain
Pride of the Invicible Overlord
Relentless
Invincible
...
Moniker of Insufferable Arrogance
Post Dated Check Loan
Predictably Damaged
Toenail
Serial Peacemaker
Check out Schlock Mercenary...there's plenty of good inspiration for ship names from the pretentious to mocking. And it's a darn good web comic too.
Otherwise, Babylon 5 had a pretty nifty naming scheme for Earth Force destroyers: they were mostly named after Greek heroes:
Aggamemnon
Achilles
Hector
Diomedes
Odysseus
Theseus
etc.
That sounds dignified and powerful (as long as you're not on the Oedipus

.
You could also take a bit more modern tack and just name them after famous leaders:
USS John Paul Jones
USS Abraham Lincoln
USS Karol Wotylja
USS Ronald Reagan
USS Hillary Clinton
etc.
Such names can also be either a blatant or a subtle political commentary depending upon how they're used.
CMS [Confederate Martian Ship] Matthew Dyment--who's he? Oh, he was the first president of Mars Colony and wrote their Declaration of Independence in 2113. It can also be a way of introducing your alternate history for the campaign world to the players in a subtle and organic way.