This is the question for the ages, and is a very individual question.
The longer you wait to collect Social Security, the higher your monthly benefit will be until you reach age 70, when increases stop (unless there is a cost of living increase). If you do not need the money at age 66, and you think you will live long enough to make up the difference between receiving checks at age 66 versus age 70, then it is best to wait.
However, if you are married and your spouse made more money than you did during their lifetime, it is best for you to take your Social Security whenever it suits you and let your spouse wait for later. This story will help you determine who should take Social Security first. Again, life expectancy issues play a role for each individual.