As a reader, I have the opportunity to come here and search for answers based on what is of interest to me. As a reader, I usually like to read the best answer first, so I will click on the "best" link to make sure that answer is sorted to the top. Some people, who follow the question, might want to see the "latest" answer first, so they will click on the link that sorts the latest answer to the top. I assume the "hottest" link will sort according to the answer that receives the most number of thumbs up. I actually like this feature because it allows me to view the answers according to my own interest.