^^word
Counter attacking against 1.d4?

The Benko Gambit is a strong choice, you sacrifice a pawn for a long period of Queenside intitiative.

i like the modern benoni a lot. it doesn't work against all of whites possible moves, but there are generally a lot of nice set ups you can go for after 1.... nf6 2.... c5.
this also means you can occasionally play the benko which is fun.

Although the Grunfeld has more theory than some other defenses, it's known as a flagrant counterattacking defense.
Nimzo-Indian is excellent ... which is why so many players avoid it with 3.Nf3
In this case, while the Queen's Indian is a great partner to the Nimzo, you can reduce your study by using the Bogo-Indian instead.
Currently, I play the Chigorin because it steers the game at move #2. But, I have found that Chigorin is better at fast time controls when a surprised player can't take the time needed to respond. Chigorin struggles a bit in longer time controls.
I vote for Grunfeld.

Benko Gambit, and Marshall Defense (that's like Alekhine's Defense against d4) - absolutely the most annoying things a d4 player can face, guaranteed! Won't you agree folks?
I don't think you need a sea of theory here.
Marshall Defense - this horse ruins everything and comes back in the game somehow...
Benko Gambit - You can feel Black pressuring you even in the endgame...

English Defence
Old Benoni Defence
Queens Pawn Opening: Horwitz Defence
Semi-Slav Defence
Slav Defence

I do well with the Chigorin even at longer time controls, but I know the lines really well. There is a lot of theory and if you dont know the theory it is easy to make a mistake. That said, I prefer not to play the positions where white doesnt play c4, so if I dont see c4 on move two I normally transpose to a Grunfeld set up, which I often play against the London.
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A former coach of mine recommended the Benoni. Ive never played it myself, but it may be what you are looking for. That coach plays both the Benoni and the Grunfeld and she says while the Grunfeld has an insane amount of theory you have to know, you can play the Benoni just by knowing the ideas.

Guys, the OP asked this over 9 years ago. Why are you still feeding him false responses? He is clearly looking for a one size fits all with no dense theory. There is no one size fits all, and everything has dense theory these days, even the Chigorin, Modern, Czech Benoni, Dutch, and other secondary defenses!

Guys, the OP asked this over 9 years ago. Why are you still feeding him false responses? He is clearly looking for a one size fits all with no dense theory. There is no one size fits all, and everything has dense theory these days, even the Chigorin, Modern, Czech Benoni, Dutch, and other secondary defenses!
probably not 1.c6 and 2.Nf6 except for 1.d4 c6 2.c4 Nf6 the Slav-Indian Defence
No, but I've played this position: