If I were going to re-localize the whole series these would be the titles.
How I'd do it:
Castlevania: Damn You Collision Damage!
Castlevania II: Everybody is a Liar
Castlevania III: WTF What do You Mean She's a Girl?
Castlevania: Alucard is Now a Belmont
Castlevania: Back to Whipping Like Crap
Castlevania: Shield Rod is All You Need
Castlevania: Dracula Finally Learns How to Walk
Castlevania: Belmont? Morris it is yupidedoo!
Castlevania: We Give You Two Characters to Control, but You'll Use Only One Anyway
Castlevania: DRACULA IS NOW JAPANESE LOL
Castlevania: Dracula is still japanese, and flamboyant dude is the final boss
And the gaiden games:
Castlevania: Yu Gi Oh!
Castlevania: Is She Trevor's Mom or Not, Dammit?
Sorry, couldn't resist.