With the combination of these characters in a new game announced for the 3DS, I thought this would be a good time to discover whom the community prefers.

Please state why in your post.

Professor Layton is basically Sherlock Holmes.

Phoenix Wright is amusing but Layton is more interesting, both as a character (Unwound Future) and as a mystery-solver (all of the games).

There is no way I can choose

I love them both equally

they are likable in their own way.

I personally prefer Phoenix, but most of the folks in that universe aren't what one would call Thinkers.  This comic captures it pretty accurately...

Listen I'm not sayin'

I'm just sayin'

(sayin' that the AA games would be about one tenth as long if Layton were the main character)

Actually, Layton would lose every case:  he'd know exactly what happened, but because he doesn't speak Idiot he'd fail to get through to the judge.

Layton.  Better artstyle, better setting, better gameplay, better story... just better games really.

You know what

That might actually be a good point

Layton 4 sure