When it comes to todo lists I prefer keeping it simple. Which is probably why I like Do It Tomorrow so much. It's pretty much a paper pad ui modeled after a moleskine notebook with a clean interface for quick info - date, current list, add/remove tasks, random coffee stain. My favorite feature is that whatever tasks you don't complete get pushed to the next day automatically, so you no longer have to micromanage a calendar.
Also it is Retina grade, free, and has no ads at all. If you're looking for something a lot more intuitive than the native notepad app in iOS I would check this out.