Well, someone showed me this here for a great ab workout
what do you think of this post? Any substitute for weight crunches? I'm not a huge fan of doing em.. Perhaps leg lifts?
I'm sure that would work just fine, but you don't have to only train your abs once per week, and you could also mix up the repetition ranges in a single session more. I also typically try to include a movement when my upper body is stationary and one where my lower body is stationary in my routines.