The Pirate Cap'n voice pack
I'm not just including this one because of my love of all things peg-legged and rum-filled. Bingo Bango provides some of the highest quality voice acting I've seen in the Workshop yet. He delivers his pirate-y lines with enthusiasm and an accent that doesn't induce cringing. This is a great voice pack, but I really think the community can come up with better ideas than a pirate captain. I hope to see a lot more of these added in the future. If anyone needs a nerdy twenty-something for recording lines, you know where to find me.
Vote for or against it on its Steam Workshop page