all of them but really depends on your weakpoints... that is more of a subjective request so hard to answer. If just starting out though I would say the grammar lessons are great bc it really helped me separate the different parts of the stimulus
For me, it was validity/invalidity, logic and advanced logic, and principle/sufficient assumption. That's because logic was my weakness coming in and these lessons in particular benefitted me in that way. I started with the Trainer so a lot of 7sage was not exactly new to me, but definitely an enhancement overall, if not equipping me with skills I didn't get from other sources.
Comments
And, the lesson on BR of course