spongebob
Funimation's DB/Z/GT Voices with few exceptions. I like adult Goku, Yajirobe, Young Krillin, Future Trunks, Chichi, #17, #18, Dr. Gero, Cell, Mr. Satan, and a few others but most others are terrible and annoying.
SpopngeBob's voice used to be deeper and I was fine with the laugh. After the movie Tom Kenny has been using a higher pitched version that does get on my nerves. However episodes in the SpongeBash seemed to feature Kenny's original voice and I hope it stays this way.
And I can't believe no one mentioned Sheen yet. I didn't have a problem with Jeff Garcia's voice for him or Pip, but a lot of my friends hated it.
Gah... I can't watch The Fairly OddParents without getting a headache... gah! I'm getting a migraine just thinking about it! :ack:
Timmy's voice is painfully high-pitched, especially when he's yelling. Cosmo... well, Lonestarr covered that one. Wanda's voice is just so shrill and crackly.