Best Defenses against d4?

      So recently I've been playing games with opponents that play d4. I've never bothered studying d4, and I'm terrible at playing the QGD from Black's side, and I was wondering what defenses are the best for black when faced with d4. If you're wondering, I currently play the Nimzo-Indian (as it is the only d4 defense I know). Please lists some of the defenses you play against d4, thanks!

Whenever I wonder about a line I'm unfamiliar with then I look for it's ECO Code and the codes of it's continuations. It isn't the same as getting direct advice from a player experienced in the line but the general idea is that lines which have a large number of codes assigned to them have historically been of most interest to GMs and Masters. For 1.d4, I've been meaning to acquaint myself with the QGD because it looks like that has been quite interesting to GMs in the past. But if you're already familiar with the Nimzo-Indian then maybe look that up too and see how far that has been analysed by GMs.

I'd do a little to help you get started but I'm a little busy today. We could put QGD on our new year's resolution list if you like? Good luck. :-)

white = d4 .. black = Nf6 or e6 or c5 or d4 idk

If you're shooting for relatively low theory and relatively easy to understand, I'd maybe go with

1.d4 Nf6 2.c4 e6

-3.Nc3 d5 - transposing into a QGD, with the intention of playing a Cambridge Springs with ...c6,...Nbd7,...Bb4 and ...Qa5

-3. Nf3 c5 4.d5 b5!? - The Blumenfeld Gambit, sacrificing a pawn for control of the center and Kingside attacking potential. It's also probably effective at your level because you'll get a lot of people probably accepting the gamebit (5.de fe 6.cb) which is both practically and objectively less strong than declining with 5.Bg5.

Play 1...c5

2.e4! :P

2...cxd4

3.Nf3! and if you don't also play some sort of Sicilian, you may be in trouble...

lol .. we could play a whole game this way .. so y don't u jus challenge me insted

You could opt for a Nimzo/Ragozin combo or the straight forward QGD say Lasker variation. There is also the Dutch Stonewall or Budapest Gambit, or the etc. etc. The fact is at our level of play anything is viable. You are probably best served by playing the opening via general principals and devote your time to tactics/endgames.

I suggest the benko gambit... fun and easy to learn

I like the semi-slav!

I counter that with suggesting NOT playing the Benko Gambit.  It's only half sound, if that, and attached is a game I had this weekend against a 2133 player and absolutely slapped the Benko silly.  Go with something more sound against 1.d4, like any of the 1...d5 lines!

and? if black can play d5 next move attacking whites center

Qc2?? that just allows black to exchange knights and leave white with doubled pawns and black has the bishop pair a much improved version of the nimzo indian if that case for black

lol can't belive you think that doubled pawns are good 

have you not heard of the nimzo indian if it was so that doubled pawns strenghthen your center don't you think that the nimzo indian defence would be bad since it gives up the bishop pair so the opponet "strengthens thier center" yet it is the most popular defence 

I, against d4 openings, play the Indian Defenses, which offers many opportunities, including the King's Indian Defense, the Queen's Indian Defense, the Nimzo Indian Defense (as you stated), and the Bogo-Indian Defense. If these are not sufficient enough, you could always try 1... d5, however I discourage this in my own play. You could also try the Petrov Defense, which can transpose into a Four Knight's Game, the Italian Game, and the Guicco Piano, which should provide enough variety. There are also a few gambits you can attempt, including the popular Benko Gambit. Other options include the Grunfeld (one of my favorites) or the Slav Defenses (also one of my favorites.)

i know that but in this case it is bad such as the nimzo indian where the doubled pawns are targets for blacks pieces this classic game by nimzowitch shows how to blockade doubled pawns and gain an advantage and drain out counterplay