Best or Favorite: What's the difference?

Alvina of Blue Rose Girls asks, do you make the distinction between favorite and best?

I've been giving this a lot of thought lately. Sometimes, the books on my sidebar that says "best" are really my favorites; but I don't want to change it to favorites, because it's also possible that I personally feel cold about a book but recognize it as "best" and include it.

So, go over to Blue Rose Girls, and share your opinion on best v. favorite.