I'll throw a few abs exercises in a week, but I feel compound lifts like front squats, walking lunges and even skull crushers work them more than any isolation exercises.
I used to do decline bench weighted sit ups, but I started getting sore hips and realised the angle was all wrong for abs. I think all you need are hanging leg raises, mountain climbers and Russian twists with a bit of weight.
Other minor body parts would be glutes, forearms and traps. I'll usually just do one exercise to failure at the end of a workout as they get trained indirectly by many other exercises.