Some other teams may have this now, but the Angels broadcast now has a super-slow motion camera that's really great.
The all time best announcer was Harry Carry, you could tell he was drinking, so as the game went on, he got more and more funny and off topic. It was like watching a game with a really funny and nice guy at a bar. He'd call pitches "High and outside" that were in the dirt. He was definitely a Cubby booster, but he didn't hold back criticizing bad plays.
Vin Scully is probably the most polished and knowledgable play-by-play guy, plus he's got an encyclopedic knowledge of baseball history.
All the ESPN guys are good.
I generally hate the Fox playoff guys, they spend too much time talking about everything but the game, plus, they spend so much camera time on things other than the game at hand. THey're fixated on creating drama surrounding the game, and not so much on the actual game. Sometimes, they cut back to the game when the ball is already heading toward the plate. If it's a really tense moment in the game, they'll start cutting away to fans or coaches watching to try and build up the drama visually, and I'm screaming "THE GAME IDIOTS! SHOW THE GAME!"