what is the best aggressive opening for white in longer time games?

There is no best.

King's pawn and Queen's pawn opening

You lost to a 1000 player in 11 moves.  Why do you need an "agressive" opening?

Completely understandable.  That is how i treat my online chess :-)

But to answer your question.  Forget about terms like "agressive" just find an opening you like playing and learn the basics: Piece placement, and pawn structure.  But before even that, you need to understand this:

The basics of each phase of the game

Opening:

Follow the Opening principles:

1.      Control the center squares – d4-e4-d5-e5

2.      Develop your minor pieces toward the center – piece activity is the key

Ø  Complete your development before moving a piece twice or starting an attack.

Ø  Move pieces not pawns.

3.      Castle

4.      Connect your rooks

Ø    By move 12, you should have connected your Rooks, or be about to do so.

Middle game:

When you have completed the Opening Principles, you are now at the middle game.  Now you need to formulate a middle game plan.  The middle game is a very complicated part of a chess game.  A simple way to develop a middle game plan is to perform the following steps.

1.      Scan your opponents 5^th, and 6^th ranks (3^rd, and 4^th if your black)

2.      Look for weak pawns, and or weak squares.

Ø  Weak pawns and squares are Pawns, and squares that cannot be defended by another Pawn.

Ø  Knights are excellent pieces on weak squares.

Ø  When deciding on weak squares, and weak Pawns to attack, the closer to the center the better

End game:

Start with the basics:

1.      Learn basic mates – KQ vs. K, KR vs. K, KRR vs. K

2.      Learn Opposition, and Key Squares

3.      Learn basic King and Pawn endings

Pre Move Checklist

1. Make sure all your pieces are safe.

2. Look for forcing moves: Checks, captures, threats. You want to look at ALL forcing moves (even the bad ones) this will force you look at, and see the entire board.

3. If there are no forcing moves, you then want to remove any of your opponent’s pieces from your side of the board.

4. If your opponent doesn’t have any of his pieces on your side of the board, then you want to improve the position of your least active piece.

5. After each move by your opponent, ask yourself: "What is my opponent trying to do?"

Not really sure Queen's pawn games compare in terms of "aggressiveness."

Basically what diakona said.

To avoid all the theory of stuff like the Ruy and the Italian, I'm personally warming up to the Scotch, but it really depends on your style. Play a few games with some different openings and see if you like the positions you tend to get out of them.

d4 (black gets to choose the opening. i like d4 because there are generally less trades than e4)

This guy does an excellent job of breaking down, and explaining middlegame ideas.

https://www.youtube.com/playlist?list=PLC1283332FD485C40

The February 2017 issue of Chess lists the top twenty openings compiled from a list of 4561 December games where both players were rated over 2400 Elo. One can not take position on this list too seriously because it is greatly influenced by how the openings are grouped. For example, all the Retis are grouped together, while English is separated into 1...c5, 1...e5, etc. Nevertheless, for what it is worth, some of the list entries are: 336 Retis, 198 King's Indians, 186 Caro-Kanns, 159 declined Queen's Gambits, 158 Nimzo-Indians, 148 Najdorf Sicilians, 135 Slavs, 128 1...c5 Englishes, 114 Kan Sicilians, 102 Italians, 98 1...Nf6 Englishes, 97 Queen's Indians, 88 1...e5 Englishes, and 78 Berlin Ruy Lopezes
For someone seeking help with choosing openings, I usually bring up Openings for Amateurs by Pete Tamburro (2014).
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
I believe that it is possible to see a fair portion of the beginning of Tamburro's book by going to the Mongoose Press site.
https://www.mongoosepress.com/excerpts/OpeningsForAmateurs%20sample.pdf
Perhaps Fenix613 would also want to look at Discovering Chess Openings by GM John Emms (2006).
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
"Each player should choose an opening that attracts him. Some players are looking for a gambit as White, others for Black gambits. Many players that are starting out (or have bad memories) want to avoid mainstream systems, others want dynamic openings, and others want calm positional pathways. It’s all about personal taste and personal need.
For example, if you feel you’re poor at tactics you can choose a quiet positional opening (trying to hide from your weakness and just play chess), or seek more dynamic openings that engender lots of tactics and sacrifices (this might lead to more losses but, over time, will improve your tactical skills and make you stronger)." - IM Jeremy Silman (January 28, 2016)
https://www.chess.com/article/view/picking-the-correct-opening-repertoire
http://chess-teacher.com/best-chess-openings/
https://www.chess.com/blog/TigerLilov/build-your-opening-repertoire
https://www.chess.com/blog/CraiggoryC/how-to-build-an-opening-repertoire
https://www.chess.com/article/view/learning-an-opening-to-memorize-or-understand
https://www.chess.com/article/view/the-perfect-opening-for-the-lazy-student
https://www.chess.com/article/view/how-to-understand-openings
https://www.newinchess.com/Shop/Images/Pdfs/9035.pdf
https://web.archive.org/web/20140627110453/http://www.chesscafe.com/text/hansen169.pdf
https://www.newinchess.com/Shop/Images/Pdfs/9029.pdf
https://www.newinchess.com/Shop/Images/Pdfs/7277.pdf

pretty sure the King's Gambit is as aggresive as it gets from White's perspective. not my cup of tea though

1. c4 has been proven to be the most terrifying opening move. Most opponents I have played OTB simply resign at this point. It definitely strikes fear into your enemy's heart.

The King's Gambit is usually named as most aggressive in the 1 e4 e5 openings.  You can also often get-in an early f4 in the Vienna and Bishop's Openings that strike quickly toward Black's King.

The Bishop's Opening also boasts the Urosov Gambit, 1 e4 e5 2 Bc4 Nf6 3 d4!? exd4 4 Nf3 (inviting 4...Nxe4) about which there are a lot of books and YouTube videos describing traps, etc.  Personally, I intend to fool around with it myself a little bit when I find a need to take a break from tactics, tactics, tactics - which is what you should make sure you're good at before taking on aggressive openings.

If 4...Nxe4, Gary Lane in The Bishop's Opening Explained (2004) notes: "This is fairly standard at club level due to some old books that favored Black. But nowadays it is frowned on by experts because it presents White with a wonderful attack that is difficult to resist."

Of course, if Black plays 1...c5 (Sicilian) then maybe the Smith-Morra Gambit or if 1...c6 (Caro-Kann) the Panov-Botvinnik Attack or if 1...e6 (French) some variation of the Advance Variation.  You obviously have to adapt to what Black Plays.

As Black, most feel the Sicilian is fairly aggressive and has the best record among all Black openings.

whatever opening you prefer,and play best with.

Grob's Attack?

he means,sound openings aswell.