Voice Acting - Good or bad?

I've decided to make this topic after the recently revealed news that Sonic and Tails are to get new voice actors. What is your opinion of voice acting in games? Do you like it or not? Are there any games where voice acting made it better or any where it made the game worse? What games do you want to have voice acting?

I personally like voice acting, but I dislike the push for games to have them. There's reviewers who rate games lower if there's no voice acting, such as in Twilight Princess, but did Twilight Princess NEED voice acting? I mean, we've gotten so used to Link being silent that him having a voice would be weird. Reviewers rating a game lower for no voice acting can have a negative effect on things. It's just like people who rate games lower for no WiFi when they don't need it.

As for games that had good or bad voice acting...a good game is Tales of Vesperia. I loved the voice acting of many characters, just not certain ones like Karol. God, I'd like to kick Karol through a window. Anyway, a game with bad voice acting is Sonic The Hedgehog for PS3 and 360. It was so cringeworthy and just awful, and added to one of many things I disliked about the game.

Finally, a game that needs voice acting? Pokemon Black/White. A few of the new features would be good if they had voice acting, but I can imagine the voice acting being awful. Still, it'd be neat to see.