Hey RJ'ers

I am doing training about 4-5x a week at the gym but I want to concentrate and develop my abs/obliques more. I am setting up a routine to do before bed, just on the floor of my room. I want it to include upper/lower abs and obliques. I have some exercises that I would like just for strength training (pushups and spidermans.) If you have any must do exercises please let me know what they are and I can include them. So far I have:

Exercise ball crunches
Leg raises
Vertical leg crunches

Any input/suggestions would be appreciated, thanks dudes