Black's best response to d4?

Hello everyone. I play the Scandinavian/Center Counter in response if White plays 1) e4 so whenever I play in OTB tournaments as Black and my opponent pushes 1) d4, i'll just explode. Im not a Preminum member in chess.com so unfortunately I can;t go deep into the Game Explorer. So what is Black's best response to 1)d4? And also which is the best GM that plays that opening/variation, so I can go through so of his games. And are there any books on that opening/variation? Thanks for all help :)

EDIT : Ok, scrap the "best" in the title. What im asking for is what you reply to d4 and why? And which is the most aggresive variation, because im not really the passive type.

2nd EDIT : Im choosing to play the KID. Any criticism is welcomed :)

3rd and hopefully FINAL EDIT from me : After long analysis and lots of criticism from people, I finally decided on playing 1) ... e6

Why I chose this :

- I doubt many people who play d4 at my level now how to respond to this, therefore im taking them out of their main line and bringing them to a completely new opening to them where they have to play to their knowledge whereas im prepared.

- If 2)e4 then I can tranpose to the Scheveningan which I am currently studying.

Scandi, after 1. d4, white would seek to advance next with e4, so your next move better stop that. Here are the possibilities:

1. d4 d5 is standard, black mirrors white to get a share of the center.

1. d4 Nf6 can transpose to those hypermodern/indian defenses which are effective but verrrry complicated in learning.

1. d4 f5 is the Dutch defense, a risky one to play that's not too popular. However you can play this to reach a Stonewall or a Leningrad that can be good.

After 1)d4 d5 2)Nf3 then what do I play? I know the Slav so 2)c4 shouldnt trouble me. 

Say what? 

I know the Slav, but im not good at it :P The reason I created this thread is to find new variations/openings against d5 other than my already known Slav. Lately i've found the Grunfeld Defence so im going to analyse and see if I can use it. I prefer to play lesser known/expected openings. Yes, I know Nc6 is first in the Games Explorer after 1) d4 but still :)

1. d4 d5 2. Nf6 Bg5 is the trompowski net for white which will give up the bishop pair but have the double pawn for black

Would suggest sticking with slav, because it is one of the simplest and most popular opening to play OTB. This is because it is easy to understand, it is based around developing Bc8. If jump to another opening just going to run into problems with that. Especially if it is a highly theoretical and risky opening like grunfeld.

A small modification chould make is playing a6 slav, instead of the main-line d5xc4 then Bf5. This avoids giving up center to develop Bc8, because can answer Qb3, after Bf5, with Ra7, or b5.

I did mention I like lesser known openings :) But thanks for the advice. I wont just immediately into Grunfeld or any other variation. I'll analyse and prepare for it more thoroughly first :)

I wouldn't have said the Slav was an "easy" defence, there are plenty of lines for white to keep black on his toes...

Personally I play the Slav against stronger players (as it's a bit more "solid") and use the Modern Benoni against players of similar to weaker strength to myself (I find it more dynamic and fun to play)...

I usually play the Dutch/ Stonewall which prevents e4 immediately, but it locks the game. You also have to be careful with the Staunton gambit continuation or bishop to g5 move, which turns the game into a different structure than the typical Dutch.

Most people however dont go this way, so I recomend try a few games using Dutch

That I guess is another reason I don't want to pick up Slav. Always on my toes as Black. But I guess I will be doing further analysis to both Slav and Grunfeld.

Thanks for the recommendation, will look into it :)

Well nothing in chess is exactly easy, which is just as well really as would all be a bit pointless. Would say slav is one of the more straightforward respones as in all lines black aims to solve the Bc8 problem, and develop the peices. Against main line like 1.d4 d5 2c4 c6 3Nc3 Nf6 4Nf3 need to know something concrete because of pressure on d5. Only opening more basic would be the Queens Gambit declined. In all honest though if the OP is struggling with Slav, don't rate his chances of learning the Grunfeld too highly.

If really determined to try Grunfeld though there is Avrukh's two volumne set from Quality chess, and Yelena Dembo wrote a decent book few years back. Currently it is highly trendy with elite FIDE 2700+ players so it is not exactly unknown, and the theory is changing rapidly.

Best reply: d5/Nf6!  It depends on your opponent's style of play!

Im not struggling with Slav, im just not as interested in it :) Will certainly look into the books, thanks :)

I'll be being Black, my friend, not White.

for me any response will do but best for every player is to mobilise thier officer as quick as possible and think depply everything counts!avoid any mistake

Slav makes the most sense.  Semi-slav if you're ambitious. If you're alread a fan of the Scandi, the pawn structures of those defenses have a strong tendency to be the same as or similar to the Scandi (all Caro-Slav).

You might consider playing through either a QGA move order (with 3...c6), or a Triangle move order, if you don't like certain lines.

My Scandinavian Qd6 goes with a6 and possibly b5. But anyway what is Semi-Slav? 

I think I might reconsider my dropping on the Slav and taking up Grunfeld instead since everybody is recommending the Slav! Thanks everyone who did :)