Pet Peeve: People beginning an answer to a question - or beginning anything - with "So...".
Interviewer: Explain to us how you came up with the idea of mustard-flavored carburetors.
Interviewee: So... I was sitting in my basement...
It irritates me a lot, mostly because people who do this do it almost every answer in an interview, and also because "So...." isn't proper used that way.