In general, I think the only caster who is hypey enough is gecks (besides cbear) and I really feel like most casters undervalue this quality. if you get hyped up for big frags, multi kills or whatever, it will get the viewers hooked into the game instantly. I've even found myself reacting in my chair with a big "WHOAAA" if the caster is making it exciting, If they are talking like they're narrating its really hard to get into it or stay focused on the game.
That being said, I think casts really need a little bit of a play by play hype caster and just 1 analyst to chime in during a bit of the downtime, the play by play caster should be doing 70% of the casting IMO.