My favourites will always be the ones that actually illuminate the match and show you things you hadn't thought of: Neville, Souness, Nevin.
I can't stand listening to Carragher or McManamanamanaman, not only because of "the noise" but because they don't say anything you don't already know. Roy Keane just gives me the twitchy shoulder like it's getting ready to punch the wanker in the face. And he's another one who gives no more tactical insight than the bloke stood next to you on the terrace. And as much as I love the guy, I'd place Micah in that category too - you're just saying what everyone is thinking.
So yeah, pundits that actually make you think v pundits that just sound like they've been stood next to you at the match.