Morgan Freeman
Wouldn't it be sweet if they released ghost dlc packs for like 50 cents or a dollar and you could have a celebrity as your ghosts voice and you would swap between them depending on how many voices you bought
Samuel L. Jackson would be hillarious. "There's too many mother-blam!-ing Hive on this mother-blam!-ing Moon!"
Edit: saw another guy post it, Robert Downey Jr. would be awesome.