The obvious candidates include Paul Morphy, Adolph Anderssen, Rudolph Spielmann, Alexander Alekhine, David Bronstein, Paul Keres, Rashid Nezhmetdinov, Mikhail Tal, Efim Geller Gary Kasparov, Alexei Shirov, Vasily Ivanchuk, Judit Polgar, and Alexander Morozevich. I'm sure there are plenty others.
Some of the best American attacking players include Harry Pillsbury, Frank Marshall, Kamran Shirazi, Larry Christiansen and Hikaru Nakamura.
But in order to be a truly great attacking player, you have to be able to see when the attack doesn't work and how to bolster that attack.
Of that list, Alekhine, Tal and Kasparov are probably the best attacking players of all time.
Already to post #19 before the first Shirov mention. A travesty.