Grunfeld: Best Opening Ever!
I think it's theoretically great, but practically..not so much. I mean, the huge amount of theory you ned to play the gruenfeld well is ridiculous when compared to any opening, and yet you can't even be sure of reaching a gruenfeld and need an additional extra system to play against 3.Nf3 and other moves.
I've always kind of wanted to play it, but couldn't help but wonder if equalising is really worth the huge amount of learning and upkeep the gruenfeld requires at amatuer level.
It's the choice for Black against 1.d4 in GM Larry Kaufman's book. http://www.amazon.com/Kaufman-Repertoire-Black-White-User-friendly/dp/9056913719