Pirate Queen x Cabin Boy sounds interesting~ But so does many of your others, it is really hard to decide, Like I find something n every category except the Futuristic/Scifi one. Like Butler x Mistress~ Tough Girl x Shy Guy too. Ghost x Human~ DEATHNOTE, Harry Potter, Naruto, Future Diary, A:TLA, FMA:B, X-Men, Batman (Nightwing or Dick Grayson Batman), Teen Titans. Like the first 3 just strike me as epic (Star Trek < In to Darkness). Anything Mass Effect related is up for game too. 

Of them all I think I lean more towards the Butler x Mistress.