If there is one thing I would take many current commentators to task for, it's the 'continually astounded' voice.
The 'have you ever seen that before' or similar - at an 80% increase in volume. Trying to periodically whip up excitement - or calling the game like it's the first one they've ever seen.
The Channel 9 commentators - Thompson & Psaltis - are particularly noticeable for this. They both sound like blokes from the local pub doing their first commentary stint - after they've each had a few beers. Amateurs.
The Fox commentators - the actual game commentators, not the 360 pundits - are ok by degrees. Parker & Ennis - I'd be happy never to hear them again, their particular bias in various directions are so strong. Warren Smith - ok I guess, Brandy = accurate most of the time. Voss = full of himself. Speed & Russell = chock full of bias towards particular teams. Ginnane - ok, just loose the 'gooooodbyyyyeee'......it's getting old quickly.