Paul Morphy (3000)???
Was Paul Morphy the best open game player?
Take a look at this incredible game played by Kasparov as Black. Morphy never played anything approaching this game in terms of complexity. Brilliance is a bit subjective, but I'll take this over any of Morphy's brilliancies, and this may not even rate as one of Kasparov's 100 best games!
Bxe4 was a great move. The rest were standard Najdorf Scheveningen moves. :) RxNc3 is one of the first things Najdorf Scheveningen players learn to look for. :D
Not saying that Kasparov wasn't a great player--one of, if not, the best. But I think that game pales in comparison to, say, one of Morphy's:
And for fun, here's a short story of what happened the day Kasparov played against Morphy (Hint, a rook sac is involved).
22. Kb2 looks to me to be the fatal move for Bird. 22. Kc1 may have been better sticking close to his Queen and Rook instead of exposing the King further.
Carlsen's greatness isn't doubted. He definitely can play the open positions, but he isn't really known as a great attacker. He's better known for reaching an equal quiet position and outplaying his world-class opponents as if they were fish.