work on losing the fat off your gut, and work your abs like you'd work any other muscle group where you need growth. This means add resistance to your ab workouts. Dumbbell between legs, ankle weights while doing leg raises etc.
As for best ab exercises? Who cares, that's not super important. What "I" think is the best is probably not what others think is the best, so go by personal preference on that one. Do ones that YOU like doing, come up with a routine that fits YOU. That's how you'll really see results.
