Agressive response to 1.e4?

If you really want to be aggressive, the Sicilian Dragon is the best option. You'll have to learn a decent amount of theory, but it forces white to play cautiously, and black is usually on the attack by the middlegame.

 Did you even read the original post?

 I'd question this too.  Playing "cautiously" against the Dragon is a recipe for defeat -- if anything, that opening forces your opponent to attack you vigorously, and provides several strong plans for doing so.  It certainly produces exciting chess, but at the present time theory says that White has the better chances.

Agressive responses don't always score well against some of White's openings. (e.g. The Latvian Gambit) What you need is a strong response that will generate plenty of counterplay while allowing you to also have good defensive play.

The three defenses I have found to be best for this are: 1. the King's Pawn Game (1.e4 e5 and all other variants such as the Ruy Lopez, Two Knight's Defence, Four Knight's Game, and Guioco Piano.) 

2. The Sicilian (1.e4 c5 and all variants such as the Dragon Variation, Poisoned Pawn, Scheveningen, Kalashnikov, and Closed Sicilian.)

3. The French Defence.(1.e4 e6.)

Some might argue that the French is too cramped, or too defensive, or too passive. It is true that the French defense has the obvious drawback of blocking the queen's bishop, but this is usually compensated by good knight play and a strong counter-attack in the center early on. In fact, this defense is extremely difficult to defeat simply because of Black's cramping in the center.

In addition, the Caro-Kann is often safer than the French; but offers fewer opportunities for counterplay. I still play this defense on occasion; because it cramps a knight instead of a bishop. However, it is not as agressive as the openings you are looking for.

These choices exclude gambit for Black not because they are no good, but because it can be safely assumed that all of Black's gambits that are sound will offer good counterplay opportunities anyway, and thus they are inherently aggressive to begin with.

Note: The Scandinavian Defence (1.e4 d5!?) is nowadays regarded as an inferior response to White's move because Black gains nothing but a waste of tempo with his queen. It is common to see amateurs play openings like this one, but most Grandmasters don't; so why should you?

I most wholeheartedly disagree. In the Scandinavian 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 line, which I believe is most commonly played, it is difficult to say that Black lost a tempo. Oh, Black moved his Queen twice? Big whoop. White has developed one piece, Black has developed one. If White continues to chase the Queen, he will most certainly end up at least with an inferior position (in the Center Counter White usually has plus-over-equal), or likely be a pawn down in the opening or worse, which is worth three tempo or so I've heard. Black aims for quick development and light-square control in this line, and is perfectly fine.

That's just the 3...Qa5 line. There's the 3...Qd6 and the 2...Nf6 (with some aggressive gambits to boot, for the gambiteer) lines to consider. There are also the lines where White declines to take the d-pawn, which are generally good for Black (I've found those get played often in Live Chess here, because either they don't know the "main" lines of the Scandinavian or they don't have the databases and such to help them as in Online. This puts your opponent in your territory during the opening.).

No, it is not as solid as the Caro-Kann, but there are always tradeoffs and we are definitely not discussing grandmaster play. The reason I suggested the Scandinavian is because it closely fits the criteria the original poster was looking for:  aggressive, not loaded with reams of theory, and it puts the opening in Black's ballpark.

I think the sicilian is your best bet for aggressive, tactical play. However if you don't want to learn the theory than 1...e5 is probably the best choice. The french can be played pretty aggressively though, especially lines like the winawer poisened pawn, but again that is alot to learn. In my opinion, the caro-kann or the petroff gives black a solid game, but hardly any scope for a counter attack.

Thanks for all the input everyone. From what I've gathered, it seems like I can use 1...e5 to try to switch to a style that involves more counter-attacking. I've also heard that playing 1...e5 is good to improve your positional play so I guess I'll be going with this for awhile. All new opinions are still welcome as they may help someone else make up their mind regarding opening decisions.

1...e5 as a response to e4 is the all-around best responce at all levels the only problem with it is the ridiculous ammount of theory to be learned to play it properly.

They are way's to avoid alot of the theory behind 1.e4 e5

Well, I'd rather not avoid the theory now because I'm trying to become a better player in the long run. By learning the theory behind the different moves now, I'll be better off in the future as I advance as a player.

sicilian particularly dragon is a good one if your willing to put up with losing for while till you get the hang of it.

I wasn't saying that you should try to avoid learning any opening theory, but you should play openings that are at your level of understanding. I would just play simple openings so you can focus on improving your middle. It's not practical to study openings really in depth so you can go into the middle with a small advantage, if you can't convert that advantage in the middle game. 

If the mistakes that determine the game are made in the middlegame (typical) then spend time on the middlegame. Opening study is often useless.

Yeah I have problems in all three areas of the game. I can make mistakes and lose equal endgames, drop a pawn in an opening when I'm not paying attention, or overlook a tactic in a middlegame (more likely I just move my piece to a place that allows a tactical strike as opposed to my opponent successfuly hitting me with one and me not noticing.) However, in the current opening I play, the conflict is delayed too much and often I get into an endgame before I get a chance to really get into a good middlegame position. That's the main reason why I want to revamp my opening repertoire.

My personal favorite is Pirc (1. ... d6) it's an opening that starts out quite defensive but gives very agressive possibilities in the late opening and middle game. If white doesn't know it well you'll demolish them.

Clarification: "Opening Theory" has a particular definition in chess. It doesn't mean the ideas behind the moves, it means the body of known moves in the openings. If it hasn't been played or published etc., it's not part of opening theory.

I think Spiffe gave you some pretty good advice!

NesimTR asked: "I just want something that I can play to give white problems if I can take the initiative. I know that 1...c5 is one option but what about 1...e5? Would e5 be considered an aggressive response against 1.e4 and if so, what variations would I be able to use to give myself attacking chances against white?"

I always play !.e4 and the Opening that gives me the hardest time is 1. ... e5!

Because they are playing for control of the Center and rapid development as well! And if Black plays the Two Knights Defense they are actually developing threats that White has to answer, It is Blacks best attempt to sieze the iniative!

There is a fair amount of theory you should study as far as The Ruy Lopez and The Two Knights Defense, but certainly no more than you need to know to play the Sicilian.

c6, great move, planning, d5, very aggressive  Grrrrrr 

Sure, black is ultimately fine in the scandinavian, especially with the solid ...Qa5, but if black doesn't know what he's doing white will have a comfortable advantage. White will have a pawn on d4 and knight on c3, plus black's queen had to move. That's enough for white to generate good play at amateur level and grandmasters don't like it because it gives white the initiative. He has more central space and a slight time edge. Yes, if black chooses ...Qd6, then he is fighting for the initiative, but that doesn't mean he gets it. It usually ends up exposed there. The sicilian is sounder and also plays for the initiative. But ...e6 I think fights for the initiative also!If he destroys white's center, usually his central majority then becomes very strong as long as he can move it. I think 1 ...d5 and ...Qa5 is out of fashion because black doesn't get many favorable imbalances, just a queen on a5 and a solid position but ...e6 directly attacks the white center and ties his pieces down.