Planks are effective (put your feet on a bed end or a couch and hold your body up in a straight line for 30 seconds, two intervals), figure four crunches (cross one leg over your opposite knee and crunch up while pulling your legs toward your body), Sit-ups with a twist are good for you as well. There really isn't an "easy" way to get six pack abs, but there are ways to help shred your ab area in order to flatten, tone, then sculpt. Like LB said, any core exercise should do the trick (I do those at least once a day) and the best results come from when you feel that burn in your abs and you keep going.