Marvin Harrison is a reciever that I believe is on the same level as Randy Moss or Terrell Owens skill-wise. But he is boring. I would much rather watch Moss or TO. Their unpredictable behavior keeps me interested.
And then fans like myself were impressed listening to an interview with Terry Holt because he did a 30 second clip on Mark Bolger without saying "uh" and "ya know" once (or talk about himself). He was very articulate, which also shows in his approach to the game. Marvin Harrison is boring because he lets his game do the talking rather than flapping his jaws? As we do potayto, patahto, I guess I'll take boring. Also, his "boring" ways makes him the actual best receiver in the game, while all the other two you mentioned can do is try to talk up their game to his level.