I looove when characters go through dramatic stuff so they can grow from it! For me it gets boring fast if they aren't struggling, so I agree with you! And Allen is great! I like Komui too, for that matter. He puts up with so much. He has sacrificed so much even though he isn't on the front lines. When the Black Order gets attacked, somehow he manages to hold it together even when Lenalee has to give up more of her freedom so she can fight properly. Though he almost didn't. That is one of my most favorite parts of the manga, when all of the regular people without abilities had to band together and hold out against the attack.

So on that note, Komui, Johnny, Reever, Allen, Lavi, Bookman, and Link are probably my biggest favorites!