Who is the best-attacking player all the time? Bobby Fischer, Garry Kasparov, Magnus Carlsen or Mikhail Tal?
There's nothing like the "best attacking player of all time", as there has never been a competition to prove that fact or find the winner. What is best to you might not be best to another person. It is more of a personal taste than anything else. For example Albin Planinc played some very aggressive games that portrayed some kind of artistry and beauty but it is hard to say that his games were among the "best" or he is the "best attacking player".