Getting muscular six pack abs is really about 2 things: diet and correct exercise. Without the two you won't get muscular and you won't be able to show off your abs.
Your workout would use a variety of ab workouts, and keep them increasing in intensity. Doing hundreds of regular crunches won't do it; up the ante with hanging knee raises, ab bicycles, an ab wheel, etc. Keep your workouts hard.
As for diet you should eat frequently, 5-6 times a day, and count calories. Eating many little meals during the day will speed up your metabolism, and counting calories will keep you slightly calorie deficient- so you will burn fat. Check out this 6 Pack Abs Diet info.