It really depends what the application is. You could use spinach - shorter cooking time, kale - longer cooking time, collard - much longer cooking or dandelion - may require blanching to reduce bitterness. Swiss chard is delicious.. are you not a fan or is this just an availability issue?
You know, if you let people know where you are, you may get better help and suggestions. So many items are regional ... just trying to be helpful. Why don't you put your location in your profile, then you're done with it and don't have to think of it again.