He wins most annoying. ;o)
Definitely the AFLAC duck. One of the best running ad campaigns ever. Doubt me? Imagine how difficult it is to sell supplemental insurance on television and yet practically *everyone* can tell you who AFLAC is and what they sell. Another thing I really like about this ad campaign is that their ads still sell their product, rather than just going for laughs but ignoring the topic of actually selling the product.
I wish more advertising were this quality.