It's self-explanatory. Poisonous barbs will only be enacted if one of my particular personal favorites is unjustifiably besmirched or something. Read it, learn it, defrost and debate it. Make your counter list. Even a counter-number if you desire. Whatever. Life is too short. If you like or dislike the choice, explaining why reinforces the debate and adds to the taste. The top all-time best actress ever is clearly Genevieve Bujold, so why list the runners-up?
The three all-time worst ever male actors are also painfully clear: Steven Seagal, Jack Black and Robert Mitchum, one two three. Moving onto the factors in by best 40 choices.....
d. character actor excellence in lead roles
e. cultural impact
Many may not have all five of these qualities, but most or all possess three or more of them. So I doubt they'll be too many surprises here. None of the five qualities are judged as more important than each other.....either they have it or they don't. So.....
40. Arnold Schwarzenegger.