These three characters were meant to represent ouside commentary on humanity. I´ve excluded characters from the last two series. Neelix was originally supposed to be such commentator but that kinda backfired. EMH might have some aspirations but he was for the most part comic relief and overloaded by personal quirks. I dont know if including Seven of nine next to Spock wouldn´t earn me eternal damnation on these boards and I haven´t seen enough Enterprise to think about T´Pol. Question is, who of these characters has the most interesting experience and is overall the best? Without trying to doubt Spock´s iconical image and Odo´s story I would like to say I like Data´s innocence and „naivity“ the most.