If you want a rock hard abdominal wall, diet is 80% of the game...but there are a few exercises that should be done with love and care. My mainstay is the "crunch" on a decline board, with thingees that hold onto your legs, so your head does not crash on the floor, and leave you more mindless, than when you stepped into the gym.
The crunch should be done slowly and with appreciation and concentration for the area to be worked...Oh yes, you will feel the burn, and when you think you can't do anymore, add five more, then relax for 30 seconds and do another 25 to 50 reps. I find 100 to 200 suit me well. I use my elbows to touch alternate kneecaps...ohhhh...It's wonderful...sure.
Then if you are really masochistic you can go to leg raise while hanging from a bar...Watch you don't go swinging out of control, and hit that hot blonde in the "bean" who you've been leering at for weeks.
My new love is the rope tuck...Get a nice foam mat, and place your towel on it...It dosen't matter whether you're headed east. Try and do a third of your weight for starters, grab each end of the rope above the knots, and pull down gently until your elbows touch the floor in front of your knees...After 20 reps, you will feel close to Allah, Jesus, Buddha, or Arnold Stang...Then do another 20, then another 20....ahhhh...you should be burning in your guts...It's a wonderful day!
Next, go to the ab pull down chair...Try to pull 70 lbs. Make sure your hernia doesn't rip open...If you can pull 70lbs, you're having a good day...I managed 5 sets of 20 today. Tonight as I lay on my tummy in bed, I will feel the glorious pain.
Tomorrow, I try 50 continuous slow reps with a 45 lb. plate for my bench press...Then proceed to an incline bench for 50 more with a 25 lb. plate. Please pray for me. I am certifiable.