Up until now my favorite ACT punctuation review was Barron's ACT 36. However, I have another favorite! I am in the process of reviewing Up Your Score ACT: The Underground Guide. I haven't finished it, yet, so stay tuned for the full review. However, I have reached the punctuation review in chapter 4, and it's pretty good. The ACT 36 review is more thorough, but the Up Your Score ACT review is funnier and easier to remember.
If you really struggle with punctuation questions, choose the Up Your Score review. If you are trying to get those last few questions for a perfect English score, go with the ACT 36 review.
A while back I wrote a full review of Barron's ACT 36 which you can read here. I recommended that you borrow a copy for the punctuation review rather than buy the whole thing. However, if you can't find a copy to borrow and you simply must have one, I include a link for purchasing below. I also include the link for Up Your Score ACT, although I haven't come to a conclusion on that one, yet.