I've never seen BE or Dexter, but I've heard good things about BE.
However, I fricking LOVED 24. I think it comes down to how much time you want to devote to it...24 was 8 seasons I believe (and a movie forthcoming
). BE is only in its second or third season, right? Not sure on Dexter, but it can't be more than 5 or 6 seasons. 24 is 24 episodes times 8 seasons...that's a lot of time to put into something. I will say that seasons 4-6 of 24 were retarded good though, and would be worth watching even if just by themselves.