Organic chemistry as a second language is always a great choice. It reads like an actual book and has tons of practice problems. I got an A in both semesters of orgo thanks to these books.
A great deal of time was spent determining the best materials in terms of practice passages, well-written test, applicability, and answer explanations. Given that pretty much everyone who has posted after their recent MCAT has said that physics, chemistry, and orgo are essentially the same (they're just surrounded by biochemistry now), that list still holds. Check out SN2ed's list here.