Japanese: Aya Hirano and Minori Chihara for Haruhi and Yuki in Haruhi Suzumiya, Norio Wakamoto for his work in everything from Azumanga Daioh to Transformers: Galaxy Force, Sakiko Tamagawa for You're Under Arrest, Ryunosuke Ohbayashi for Patlabor. Tons more but I'm tired of digging up names.
English: Chris Patton and Luci Christian for their epic work on the Full Metal Panic dubs. Also, Christine Auten, Hilary Haag, Kelly Manison, and Laura Chapman for Bubblegum Crisis Tokyo 2040.