I like to use python for most of my tool creation, mainly because it is easy and fast to create, and I can easily pass the source to the rest of my team quickly. But thats just for small things, C is definitely better for final, polished solution's.

On a sidenote, Violent Python is an excellent book. My mentor introduced me to the author, who he used to work with. The guy is a certified badass. And the book is good also.