Yes, Wrangell, this is what I meant, thank you.
I believe the general opinion is that crunches (correctly executed) are better than the traditional situp. With this said, I must say that if you are looking to EARN a desired lean torso, it is mainly brought by the diet and low body fat (and your body composition a willing participant. I say this because though we all have "abs" there not all quite made the same shapes,etc). In addition, I would put less focus on "ab" exercises, and more focus on diet and your overall weight training schedule FIRST, and then factor in a ab routine if you wish. I would include Squats and dead lifts in this weight training routine.
Just a short answer.
Before I go more in depth. What are you goals. And current physical condition?