Originally Posted by Honey Badger
Especially the animal classification system presented by the GOAT.
As OP is new and seemingly genuine, I think it is only fair to explain to him that this is a troll post. The book posted is one of the most useless ever written. If the information was ever applicable, it was 20 years ago or more and should not be considered by the OP today.
To answer the question, Small Stakes No Limit Holdem by Ed Miller is probably the best conventional poker book I read for online cash games. I cant say I had a lot of "aha" moments specifically, but it definitely changed the way I thought about poker for the better. And at 10$ for the Kindle version, even Honey Badger will only complain about the price a small amount.
I also thought the NL Workbook by slowhabit was worth the short read. I think the essay parts of the book are likely outdated and for the most part have very little value (although I think it is still good to analyze different points of view), but the test section is great for learning how to analzye hands imo. Again you don't necessarily need to take his advice on the hands themselves, but working your way through the hands had a positive impact on my game as well.