Re: Ideal Madden difficulty
All Pro.
That being said, All Pro is too easy to be realistic. It's just that All Madden is too hard to be realistic, usually requiring meta knowledge and abuse of mechanics and consistently having absurd AI performance, and so is usually not enjoyable as a result.
You have to come up with some mad scientist set of options and sliders to make it play realistically, for you. But if you don't want want to mess with that for weeks or months, my recommendation is just stick with All Pro.
All Pro is a fair balance of believable performance while also letting you win pretty much all the time if you're trying. You'll have to play lazily sometimes if you want the AI to be more threatening and have more realistic performance. But better to be occasionally bored by success than occasionally infuriated by All Madden nonsense.