Queen Pawn defense recommendations.

Hey everyone, I'm trying to decide on what defense to make my main weapon as black in response to 1.d4. I've tested out pretty much every defense, but, I'm having trouble deciding what I want to use as a main line. I've been leaning towards the Grunfeld because of the activity you get, however the only draw back I find is how much theory there is behind that opening. I was also seriously considering the Slav (proper, not the Semi-Slav) because of how overall solid it is and the fact that it relies a little more on positional knowledge then on remembering tons of variations. Anyway, I'd like to hear anyone's suggestions or ideas for any defense to 1.d4. Thanks!

I like Dutch Leningrad and Nimzo-Indian, primarily because I feel there is attacking potential for black and I understand them better than other things. Tried a bit of Gruenfeld but it seems you must know more to get anywhere and there are so many variations - which does make it interesting at least. Never played Slav but of course it is a sound choice.