Man, how I hate those threads with nondescript titles that give you no clue whatsoever as to what they're about…
"Magical systems that include other systems' practices" are obviously the syncretic ones. "Novel ideas and insights" are what you have yourself when you discover systems hitherto unknown to you. What might be a revelation to you would only raise a tired jaded eyebrow in other occultists. Right now, for example, I'm slowly working my way through the Theravadan Abhidamma, and I'm having "novel ideas and insights" all the time, even if it's been around for 2,300 years or so already. Did you know that a moment of consciousness only lasts one billionth of a lightning flash? Now you know.
Some systems look simple on paper but have hidden depths that will only become apparent in practice, or leave so much room for experimentation like e.g. chaos magic that there are simply no limits to their innovation. If you really want to compare systems, you'll have to give us more criteria than just "most comprehensive" and thought-provoking, or we're in apples-and-oranges country.
So much of occultism is experiential, even if these experiences are exclusively gathered in the armchair, and you can even get your mind blown by a small remark an author made just in passing. On the other hand, some of these humdingers are right in the open, like the Buddhist doctrine of no-self/non-self - just test your current belief system against the notion that there's no soul, and whoosh (or not, depending)! That idea has been likewise around for 2,500 years, and it's not even a magical system, strictly speaking. The most sophisticated system won't have any impact on you if you're not ready, find it boring, or too abstruse.