Below are snippets from the first and last five years, but you check out the full size chart and article here.

Looking back, it’s kinda surprising to see AOL at the top of the list, which actually continues on until 2002 until Yahoo takes the top spot.  Penthouse was also a bit of a surprise, you’d think Playboy would have topped them.  Google won’t even make the list until 2001.  I would have never guessed that Yahoo took the top spot in 2013.