Well, they all have different angles. Some feel safe - like Emerson. Some need a bit of work - like Thorne. Some seem fun - like Felix. And Bale - well, some have even been offended by his abrasive nature. But maybe there's something else there once you understand him properly?
As a developer, I'm not allowed to really have a favorite, my job is to make all of the routes rewarding to follow :) As a player of many, many VNs though, the archetype I often am interested in is the shy guys - getting to know them, earning their trust, watching them unfold and grow. In my game, that'd be Thorne.