No. In my opinion dating your best friend will end most of the times in tears and you will lose the friendship. The dynamics and what we ask from a partner are different than what we ask from a friend. For my friends I can accept a lot of thighs that I wouldn't accept on a partner. For example, I don't care if a friend drinks a lot, or don't wash much, or don't like working , or this or that or the other you get the picture but I could not accept the same things for a partner.
I think it is best when that happens, but it is not a conscious decision. If it just naturally develops into that. That is when it is the best. However, I am not saying this works for everybody. It just what has worked for me so far.
Friendship is friendship and dating is dating. If you're not at least a little bit attracted to them to start out with, then friendship can't be a romantic relationship. If you're best friends that means that you were friends for a long time without attraction, so nope.
However, I think that a few months of being friends before dating is ideal, because that's the best way to know if you even want to go out with them and if you're compatible.