BDG.
Any simple, but aggressive openings for white?

I forgot exactly what it was that surprised me one time in a club game. Something like a stonewall setup and then wiggled all their pieces to the kingside for a huge attack... but IIRC it wasn't a stonewall?
Anyway just learn how to set up some positional attack and it will surprise unstudied players. I'm thinking of KIAs, stonewalls, that sort of thing. Understand a few basic ideas like opening files in the center or on the other side of the board is something they want to do to generate play before your attack gets too dangerous. That way you can avoid it if possible, and just concentrate on your attack. In the quadrant of the board where their king is, if you outnumber defenders by 2 or 3 then start looking for sacrifices and forced mates.

Gambits for white are pretty good, so look at those. BDG, KG, Danish etc.
Are they simple though? Or do you have to learn tons of traps?
Well, I guess there are no "simple" aggressive openings, you always have to learn something. But I think adopting some system is pretty close anyway.

Queens Gambit isnt aggressive
BDG isnt simple
When i look at your rating, i think you shouldnt waste your time with openings and focus on tactics and general principles...
Play the London System...its simple and easy to learn, because you choose the same set-up for most of black replies.
You can play it aggressive, when you know how...but first of all, you have to learn tactics and avoid losing material.
Queens Gambit isnt aggressive
BDG isnt simple
When i look at your rating, i think you shouldnt waste your time with openings and focus on tactics and general principles...
Play the London System...its simple and easy to learn, because you choose the same set-up for most of black replies.
You can play it aggressive, when you know how...but first of all, you have to learn tactics and avoid losing material.
BDG is extremely simple. That doesn't mean it's easy. Just that it's easy to get into, and to know how you've got to play once you're there.. And once you get there, you've got that aggressive middlegame the OP wants.
London is simple aslo, but once you get to the middlegame, you're either stuck trying to play aggressively in an opening that requires much more creativity to do so than the BDG would, or you've got to play positionally, which you can't at that level.
The only thing that makes the BDG "less simple" is the fact that the openness works both ways. This is a good thing for a novice player.
BDG is a better answer.

Roman Dzindzichashvili had a good advice:
"Laziness and tactical openings don't combine well, if you want to play tactical you will have to learn the most. "
I'm not saying you are lazy but if you want to be aggressive it isn't that simple like that. As suggested London system or Stonewall Attack are pretty simple and decent to learn.

Danish is nice and gives a really easy buildup. So does the Dutch with black. Kings gambit is great too, but some of the lines are very forcing
To quote :
"Or the queen's gambit, also very simple."
You have to realize, that your level of play will influence your notions of how simple an opening is. Sure, it's simple to play c4 after 1. d4 d5..and then you're 'in' the QG...but the QG is far from simple. Take a serious look at the Botvinnik, the Meran, or Moro's line in the early dxc4s.
Anyway, if you want to play aggressive tactical chess..focus less on openings that may or may not give you tactical circumstances and learn about dynamics and piece play. Learn about the initiative. And practice tactics. At your level, you shouldn't be worried about 'tactical openings'.

What about the Smith-Morra? I don't really know it's a complicated opening. All openings are. I like the QGA as white, it's open, and I play it a lot. See my games and you'll know what I mean.

The scotch gambit:
Wow, thank you so much. This opening is just what I was looking for :)
I´d also go for the Scotch - immediate and violent attack on the centre, good fun. King´s Gambit is also fun but a minefield, and you have to know counters like the Falkbeer which can be very unpleasant for White.
If you want a defence for Black with similar characteristics (agressive and not over-complicated), try the Scandinavian.

To quote :
"Or the queen's gambit, also very simple."
You have to realize, that your level of play will influence your notions of how simple an opening is. Sure, it's simple to play c4 after 1. d4 d5..and then you're 'in' the QG...but the QG is far from simple. Take a serious look at the Botvinnik, the Meran, or Moro's line in the early dxc4s.
Anyway, if you want to play aggressive tactical chess..focus less on openings that may or may not give you tactical circumstances and learn about dynamics and piece play. Learn about the initiative. And practice tactics. At your level, you shouldn't be worried about 'tactical openings'.
totally agreed...+1

Queens Gambit isnt aggressive
BDG isnt simple
When i look at your rating, i think you shouldnt waste your time with openings and focus on tactics and general principles...
Play the London System...its simple and easy to learn, because you choose the same set-up for most of black replies.
You can play it aggressive, when you know how...but first of all, you have to learn tactics and avoid losing material.
BDG is extremely simple. That doesn't mean it's easy. Just that it's easy to get into, and to know how you've got to play once you're there.. And once you get there, you've got that aggressive middlegame the OP wants.
London is simple aslo, but once you get to the middlegame, you're either stuck trying to play aggressively in an opening that requires much more creativity to do so than the BDG would, or you've got to play positionally, which you can't at that level.
The only thing that makes the BDG "less simple" is the fact that the openness works both ways. This is a good thing for a novice player.
BDG is a better answer.
Sorry, but your statements are totally bullsh...
Iam playing the BDG for 1,5 years now as my standard opening with white and i can tell you, that the BDG is a monster of theory to learn.
Its easy to sac a pawn, but you have to play very precise and you should be very good at tactics, if you wanna show some compensation for it, else you are a pawn down for nothing and should consider to play something else.
Its definitely not an opening for beginners or people with a rating of 1200 - 1400.
And when you compare our ratings, then you should think about my statements...
I've been looking around for some type of simple, but very aggressive openings. Something like the fried liver attack, very simple. Or the queen's gambit, also very simple. In conclusion, I need a simple, aggressive opening that average players always get tricked into.