Note that this is not an authoritative list in any way. This is just one internet person’s internet opinion. Not everything has to be about you, gawd.
I didn't want to spend the whole list saying things I've already said, so if you want to know why I picked each book, you can check out the reviews we've written.
The Ten Worst Books in the Animorphs Series
Ifi: If you want to go get a glass of water, turn the page. If you want to get a glass of juice, go to page ten. Whoops, you chose to get some juice. Bad choice! The Yeerks win and everyone dies. The end.
Adam: They could not have missed the point more if they had tried
Ok, if we were going just by quality (or lack thereof), these would actually be at the #1 spot on the list, no question. But since the Alternamorphs aren’t technically canon, it didn’t feel right. I don’t know why. Look, this is my list. I do what I want.
#10: Book Seventeen, The Underground
Ifi: This is going to be one of those books.
Adam: This is not one of those books
Adam: This is that book
Known affectionately throughout the fandom as ‘that oatmeal book’, ‘the oatmeal thing’ and ‘Jesus Christ wtf was that about’, this book featured the Animorphs learning the ultimate secret weakness of the Yeerks, a substance that drove them incurably insane on contact: store-bought maple and ginger oatmeal. There was also a lot of digging.
#9: Book Thirty-Seven, The Weakness
Ifi: Now, class, here we can see the devolution of a character.
Ifi: Marco, and now Rachel, are rapidly being reduced to a simplistic interpretation of their most prominent traits.
Ifi: From this, we can probably conclude that the author is an idiot.
Adam: You have this down to a science, don't you?
Now, originally I was reluctant to put this book on the list because it contains one of those awesome-but-only-seen-once alien races. Specifically, the Garatrons. Or Garatron, singular. Unfortunately, he’s not quite enough to carry this plane crash (see what I did there?) of a book. Jake goes off on vacation for a few days, and the rest of the Animorphs decide to break character and go completely nuts.
#8: Book 24, The Suspicion + Book 42, The Journey
I’ve stuck these two together as a cop-out. I just don’t like Helmacrons. Adam does, though. And I feel like the fandom is split 50/50 between loving them and hating them, so half of you will agree with this and half of you will disagree.
#7: Book 48, The Return
Adam: What the heck were they on during the writing of this thing?
Ifi: This is like when you get really sick and you're fucked up on cough medicine so everything is weird as hell already and then someone starts talking to you and you have no idea what they're going on about so you just sort of nod and hope they go away soon.
Near the end of the series, David comes back with a rambling and nonsensical story about rat generals. Crayak is there too. He’s all, “Rachel, join me, and we will rule together blah blah I am Sauron.” There was potential here, but the writing was absolutely atrocious. The author could barely manage a scene transition, and it’s unclear in the end what we were meant to believe.
#6: Book 44, The Unexpected
Ifi: This has gone from rather inconvenient to a universal conspiracy
Adam: It is the author deliberately sabotaging her efforts in order to prolong this contractually obligated bad plot.
This was a boring book made possible by Cassie behaving in unbelievably stupid ways. It’s a rather shameless rehash of the Alaska book, which barely avoided making it onto this list itself. At least the Alaska book had the whole team. Half the book is just the author getting Cassie to Australia in the first place. There was one cool part where Cassie does surgery on an old dude, but that’s the only bright spot.
#5: Book 32, The Separation
Adam: What were to happen if they were to take the two Rachels, have them morph seastars again, and repeat the process?
Adam: Would it divide them along different personality traits?
Ifi: Oh God
Adam: So you end up with "Able to balance a spoon on her nose Rachel" and "Thinks she's a pirate Rachel"
Adam: And then the universe explodes.
Ifi: Good riddance to it.
The starfish book. In case you’ve forgotten, Rachel morphs a starfish, gets cut in half, and demorphs as two separate people. The book calls them ‘Mean Rachel’ and ‘Nice Rachel’, and they’re supposed to be Rachel’s aggressive side versus her normal side. But they’re not. ‘Nice Rachel’ is more like ‘Traumatic Head Injury Rachel’ and ‘Mean Rachel’ is more like ‘Pointlessly Cruel and Violent Rachel.’ Neither of them are accurate representation of the two halves of the life that Rachel lives. I dislike this book more than most people seem to.
#4: Book 39, The Hidden
Ifi: On second thought, Cassie might be right. Let’s make the buffalo an animorph
Adam: Like I said
Adam: He's accomplished more in a day then they have in years.
The buffalo book! In which a buffalo somehow manages to give itself morphing power and be more effective at kicking Visser Three’s ass than the rest of the team combined. The moral issues that arise from an animal developing higher intelligence as a result of morphing humans is waved aside when the buffalo is conveniently incinerated from orbit.
That particular gimmick aside, the plot is basically the first Megamorphs book. The Yeerks can track morphing energy, so the Animorphs are running around like lunatics, and they eventually resolve the issue by dropping Cassie-in-whale-morph on the thing that is pursuing them. I might even argue that the buffalo takes the place of Amnesia Rachel.
#3: Book 36, The Mutation
Ifi: I like how you can identify the point where the author started taking hits of acid.
The Atlantis book starts out with an interesting premise. Visser Three wants to go after the Pemalite ship, so he builds an underwater Blade ship and glues some gills to his Hork-Bajir. Not the most effective plan, but okay. Except they never get to the Pemalite ship. They are kidnapped by mutated fish-people who live in an underwater city, ruled by an insane queen. These Atlanteans, for lack of a better term, have a habit of kidnapping sailors, extracting their DNA to make more Atlantean babies, and putting the dissected corpses in a museum.
Though it is evident from the start that this is what the bad guys are also planning to do to the Animorphs, they go along with everything, and even allow themselves to be captured for absolutely no reason. Nothing in this book makes sense.
#2: Book 14, The Unknown
Adam: This is a book about aliens, right?
Ifi: What am I even reading.
The Area 51 toilet book.
I don’t feel like I need to say very much about this one. We all remember it.
#1: Book 41, The Familiar
Adam: I feel like Jake has basically been plopped into the place of some other controller in the situation, with only minor details changed to try and make him fit.
Ifi: Like maybe this was originally a fanfiction, and then the author altered it to suit the needs of the publisher?
One day Jake wakes up in the future. Okay. Except it’s a future that makes no sense. The Yeerks have won, and he’s presumed to be infested, but he’s not. He can’t morph, except when he can. Nobody knows who he is, except when they do. Marco is a Yeerk Visser, Cassie makes bombs, Rachel is in a wheelchair, Tobias is Ax and Ax is gone. Anyway, Cassie wants Jake to blow up the moon so the Yeerks can’t turn it into a Kandrona sun, a plan which is apparently not complete bullcrap in this strange alternate dimension.
About midway through the book it becomes evident that this entire thing is a hallucination on Jake’s part, fraught with inconsistencies regarding everything from Marco’s rank to the weather. This does not make a bad book, just a ridiculous one. See, despite the fact that this is all obviously fake, Jake makes no effort to break out of it. He doesn’t fight. He just allows himself to be pushed along.
In the end, it comes down to Jake having to choose between saving Cassie’s life and blowing up the moon to thwart the Yeerks. We never find out which one he picks. The author doesn’t actually tell us. Nor do we ever find out who is responsible for the trip. Nothing is resolved, gained, or learned.
The Ten Best Books in the Animorphs Series
Ifi: Right in the feels.
The story of how Edriss got her rank and subsequently messed everything up. It's an oddly compelling tale, and just when you start to feel sorry for her, she goes and blows it by being psychotic.
#10: Book 4, The Message
Adam: Pretty soon, you have people going door to door and handing out pamphlets, asking if you'd like them to teach you about cetaceans.
Ifi: HE MIGRATED FOR YOUR SINS
Despite being unashamedly silly, what with the Jesus-metaphor whale and all, this was actually a good book. We get the introduction of Ax, which is excellent, and the writing was quite good. In all, it was a lot of fun.
#9: Book 8, The Alien
Adam: So, was Ax the only single cadet on this entire ship?
Ifi: Recruitment was pretty low that year
Adam: It seems strange that he was the only one that they sent to the dome at the time.
Adam: Andalites seem the type to have a draft.
Ifi: Well maybe there were other cadets but Ax had to eat them
This was basically a book of Ax’s antics. It was the first book he narrated, and we get to see him reacting to all sorts of crazy earth things, as well as lots of insights to Andalite culture.
#8: Book 45, The Revelation
Adam: That makes no damn sense, but sure, let’s go with that.
Ifi: Eva bends the laws of physics through sheer vengeful spite
After angsting about it for many, many books, Marco finally rescues his mom! It's very satisfying to have something nice happen to him for once.
#7: Book 40, The Other
Ifi: Well that is the hands-down most romantic damn thing I have ever read
Adam: Y'know, the whole childhood romance cliche usually makes me gag.
Adam: But this book is so gosh darn cute, I am okay with it.
My only complaint about this book is that we never see Galf and Mertil again. They were adorable.
#6: Book 18, The Decision
Adam: Can I move here?
Ifi: The only downside is frog-people knowing all your embarrassing thoughts
There were not enough alien planets in this series. The entire Leera plot was amazing, and I'm sad we never got to go back.
#5: The Hork-Bajir Chronicles
Ifi: Your life sucks.
I didn’t want to include books that were not in the main series on this list, but I couldn’t help it. The Chronicles were just too good. So there.
#4: Book 29, The Sickness
Ifi: If the Yeerks flew their spaceship over the White House and said, "YES HELLO UM WE ARE RECRUITING HOST BODIES. IF ANYONE IS RIDICULOUSLY LONELY, STOP BY AND GRAB AN INFORMATIONAL PAMPHLET" the line would be out the door.
Easily the best Cassie book in the series, in which she rescues Aftran from the pool single-handedly and also does brain surgery on Ax.
#3: Book 26, The Attack
Ifi: This twist was amazing and brilliant and hey guys let's not mention any of this to Aftran, I'm sure she would not be interested in this information.
2. The Ellimist Chronicles
Ifi: This is like that part in the horror movie where the whole audience screams "HE'S RIGHT BEHIND YOU!" at the screen, to no avail.
Adam: But enough thinking, we get to go on a spaceship!
Despite having almost nothing to do with the Animorphs, The Ellimist Chronicles was probably the best written book in the series. It was a very close tie between this book and #1...
1. The Andalite Chronicles
Adam: This thing.
Adam: This thing is the best thing
I don't feel particularly obligated to say much else here. Anyway, it's time for the list you've all been waiting for...
#15. Jake’s death on the Delaware (Megamorphs 3)
Ten Fifteen Most Fucked-Up Moments in the Animorphs Series
#14. Arbron is trapped in morph (The Andalite Chronicles)
#13. Arbron is killed by human poachers (Book 54)
#12. Ant-Cassie (Book 39)
#11. BBQ Tobias (Book 7)
#10. Elfangor's death (Book 1)
#9. Ax in cow morph in the slaughterhouse (Book 28)
#8. Morphing ants (Book 5) + The termite queen (Book 8)
#7. Marco is almost trapped in flea morph (Book 21)
#6. The Saddler Incident (David Trilogy)
#5. Rachel being eaten by ants in bear morph (Book 11)
#4. Rachel getting ground up by the Veleek (Megamorphs 1)
#3. Loren's McDonalds (The Andalite Chronicles)
#2. Genocide by Jacuzzi (Book 6)
#1. Genocide for the hell of it (Book 53)