Do Cardio, especially HIIT (High-intensity interval training).
Play a sport!
Basically, to get great abs, you have to work your whole body! You must get that layer of fat off your belly in order to see abs, but before you can do that, you must cut the fat from other parts of your body. No one exercise will target fat loss around your tummy, so don't even waste your time with a thousand sit-ups (or even a single one)! Also, stay away from ab-stimulating devices cuz they are totally bogus. Remember, men, your stomach is where fat will be stored first, and it'll also be the last place you can get rid of fat. Train hard (both weight-training and cardio), eat right, and keep at it! Once you hit below 10% body fat, you should really be seeing results!