Who do you think is the most agressive player? I say tal

David Yanovsky. He was agressive not only during the game, but often after it too.

Leonid Stein was a Master of Attack:

R. Fisher by far...

Rashid Nezhmetdinov

A good choice and powerful play in the example game.

Al-Walid I (668 - 715).

Fischer was known more for his endgames than attacks.  He overwhelmed his opponents with a clean, solid style.

In chess so much depends on opening theory, so the champions before the last century did not know as much as I do and other players do about opening theory. So if you just brought them back from the dead they wouldn’t do well. They’d get bad openings. You cannot compare the playing strength, you can only talk about natural ability. Memorization is enormously powerful. Some kid of fourteen today, or even younger, could get an opening advantage against Capablanca, and especially against the players of the previous century, like Morphy and Steinitz. Maybe they would still be able to outplay the young kid of today. Or maybe not, because nowadays when you get the opening advantage not only do you get the opening advantage, you know how to play, they have so many examples of what to do from this position. It is really deadly, and that is why I don’t like chess any more. - Bobby Fischer

 Frank Marshall

Alexander McDonnell ;)

Alekhine

wow, everyone has different people :)

Napoleon was a mediocre chess player, but he was certainly way more aggressive than any Grandmaster away from the board.

Tal or Alekhine.

You guys are confusing "aggressive" with having an attacking style. Anatoly Karpov in his prime was incredibly aggressive with the white pieces. He intended to win evey game with white; he fought like a tiger for evey square, evey iota of space, and he fastened on every weakness fith fanatical determination. Fischer also fought for every point--even with Black. He played until every possibility of active play was gone, constantly probing for the slightest sign of weakness. Aggression and will-to-win takes many forms

Strange that so many of us should "confuse" attacking with aggressive.

p.s. http://thesaurus.com/browse/aggressive

The most aggressive player I ever heard of was William Watson.  Boris Spassky compared his style of play to that of a drunk with a machine gun.