Fluent, articulate and the right dash of humour. Clearly, Alexander is the best co-commentator.
I agree Vossy is good, but he's not for everyone. I appreciate his accuracy and his passion for the game, because you can hear it in his calls. Rabbits Warren is past his best but he's your old-school horse-race-type caller, the balance and tone of the call.
Vossy doesn't have that classic caller's voice, but he has the knowledge of the game and he's a very accurate caller, in the way Rabbits no longer is. I just like listening to a bloke who loves footy as much as I do.
Brandy is very good analytically, not great with his delivery, but he's insightful and not afraid to call a spade a spade. I also like Sterlo, I've said this before, he's wasted doing so much compering and less analysis. The other Ch 9 guys have the footy minds but can't get that across on TV - Joey and Freddy are amiable gibberers and Gus' ego drowns out his words.
Good summary there. I agree Sterlo is another excellent co-commentator, very knowledgeable and fair. Gould probably has the best footy brain, hence the success in coaching, but he's an egotist, and rambles on too much with tired generalisations and pretend argumentativeness. I also think Warren Smith is solid.