Im gettin close to being ripped and i been training abbs about twice a week for goin on 6 months to a year now... My abbs are lethally strong i do leg raises with 40lb dumbells between my feet and from my experience whatever exercises your doing you need to cover 4 different types of abb exercise!
1: - Core stability - Abb roll outs, Planks.... Great to work up and for future injury prevention and just good athletic ability.
2: Upper abdominals...(Situps with technique depending on levels of endurance and strength) - I do situps when i never lose tension on my abbs... I never come to 90 degrees where my back takes the tension off my core and my back never touches the floor, again, taking tension off my core... I call it 3 quarters up and 3 quarters down. I do a thing where i hold 10 seconds at each stage punching my abdomen with the side of my fist. Until fatigue i do sum more situps until i cant even lift my body off the floor and then i crunch until i'm almost crying, rest and repeat.
3: Lower abbs.... Leg raises never fails and if you want too make it intense lie on a bench press bench and slide ur bum as far down the bench as u can whilst holding onto the racked bar supported with weights. Your legs can have much further range of movement and control than on the floor. You can get a training partner to force you to bring your legs all the way pointing the ceiling as fast as possible and he will throw your legs back down or your training partner on the way up (using a boxing pad) slam you in the abbs.
4: Obliques - Now at the moment im just involving it into my upper and lower abb work outs by on the sit up version twisting my body in so the side of my shoulder touches the floor and doing the holds and twisting my body and on the leg raises i used to get them to throw my legs to the side but now i can hold the 40lb dumbells its becoming to easy and boring so i need sum ankle weights as dumbells too dangerous at speed to move. For obliques a great technique is wood cutting... its like medicine ball slams but from the side to side like chopping wood.... also sitting down and holding ur back and legs off the floor whilst slamming the medicine ball repetitively on either side. Doing different types with the medicine ball passing forward an backwards on side to side with the medicine ball is great for motivation... go for a 8kg medicine ball not a 4kg... Also side plank dips are good for obliques.... now in my opinion the best thing for them real lower core obliques, (THE V'S) is hard bag work.... that core and hips movement used in proper hook punching technique when u don't do it u will be in agony lol.
Anyways thats my lock down of abbs...
Remember, abbs is the same as any muscle... It doesn't react different to different reps or sets than any other muscle.
Remember, you cant spot train... yes you can get good abbs but unless you remove complete percentage body fat spread out all over your body (the only way it works) you won't have chiselled ripped abbs.
Remember, you can eat and get stronger and fitter whilst ripping up... WITHOUT STEROIDS! ( I do not take steroids ) Its all about eating at the right times and the right things and the right training types.
Hope i have been helpful, HAPPY ABBS!