I'm trying to think of some of the other announcers I've listened to through mlb.tv (I have to fake my IP to watch since I'm in the Detroit blackout zone and sometimes the video freaks out and I have to watch the other team's coverage). Pittsburgh and Cincinnati I think have good announcers. Maybe St. Louis too. I'm not too fond of the guys in Boston, but I love their accents.
I like announcers who compliment the other side's team and players, who are not so one sided (saying things like, "The Good Guys and The Bad Guys") that they can actually just enjoy the game of baseball and the players who play the game rather than simply being about winning and looking good.