Disclaimer: This answer is based on my experience with the exercises. Verify that it works for you (and adapt as necessary).
I haven't done the cable crunches before; as a result, I'm not certain how effective it is. But based on the videos, the range of motion indicate (to me) that the effects will be felt most on the arms and not the abs (I'd like someone experienced to validate or nullify this theory).
I used to perform the hanging leg raises daily until I realized that it wasn't really effective for the abs; it's more effective for the lower hips and thighs. So, I switched it to a different type of hanging leg raises. The posture is still the same as the regular leg raises, but instead of lifting your knees, you lift your legs together into a L-sit position. The slower I go, the more intense I feel my core tighten. You can start with 5 reps and increase it if you still have the energy to continue. I've been doing that daily ever since (I still perform the regular hanging leg raises if I have time for them).
In addition to the above, I perform reverse crunches. Make sure your butts are lifted off the floor and your hands are clasped behind your head (this ensures that only the abs are involved in the activities). Start with 20 reps and you should feel the effects on every part of your abs.
Also, I perform standing crunches (the one in which your right elbow touches your left knee and vice versa). Try to keep your torso as straight as possible (without bending). Starting with 30 reps should make an impact on the abs.
I also perform leg raises. It's similar to the hanging leg raise described above but your back is on the floor. Lift both legs together and lower them together. Also, ensure that the only time your legs touch the ground is after you've completed the set. Some people put their legs down after every rep, but I don't encourage that as it reduces the effect.. Start with 10-15 reps and work your way up.
I don't know what this exercise is called, but I recently added it to my list. Adjusting a regular bench press such that the torso region is lower than the sitting region and starting from a lying position, I perform regular crunches by lifting the whole torso from the depressed region to a full sitting position. Then, I gently go back down to the starting position. 15-20 reps of this can be tried. This certainly gives me the same effect as the reverse crunches.
I finish with the easiest crunches of all, the regular crunches. I noticed that this mainly works my upper abs only. So, I don't usually feel the effect all over the abs.
If you try these exercises and see the effects you want, ensure that you increase the reps periodically. Mix and match them as you desire (I still do them daily)
Although I do regular weightlifting, I haven't lifted enough weights (Deadlift PR is currently 270lbs - 1 X 5, Squat is 220lbs - 5 X 5, Bench Press is 160 - 5 X 5) to claim that my abs came from weightlifting. I only do them 3 days a week vs my daily crunch-aton.
Using the pictures on this link, my current abs is closer to the guy in the 11-12% body fat than the one on his right.
So, I can testify that it works for me.