While Wesley Crusher was there for the young boys and girls to identify with, I didn't like his "over the top" depiction of being such a whiz kid, supposedly leaps and bounds ahead of most adults on the ship. I would've liked seeing Wesley as a little bit more of a rebel, if not fully then just partly. Yes, he did "rebel" in the end, joining the Maquis... but it sure took a helluva long time to get there.
Anyway, if I had to leave Wesley alone then I'd say Chakotay. While I thought it was cool to bring an American Indian into the cast, and I really did like the Chakotay role, I found Beltran's portrayal to be rather flat. He's not a very talented actor. So, Chakotay was on the bottom of the list of characters I enjoyed. And... well, where he ended up afterward kind of speaks for itself.