As far as favorites I can't really pick. I kind of liked all the others but a few got on my nerves. Those are below with my reasonings.
Disliked:
Reasons:
#1: It didn't morph the same as the others and they only did the head. Put it with the rest and it looks out of place.
#2: A few others look rather digitally done, but this one is totally a sketch. It's not bad, but it is out of place.
#41: Jake doesn't actually morph into his older self and clothing doesn't morph. It goes against the rules for morphing in the book and all that really happens is he gets older.
#43 & 49: Tobias looks younger than previously. It bugged me. About the only positive is that they finally had a blond model for him.
#47 & 48: The Jake and Rachel on these look way younger than they do on any other book and these are practically the last ones they're on in the series.
#54: The overlapping heads bugged me because it's hard to tell who's who.
MM1: I didn't like the half animal face half human face personally. Most of all didn't like Cassie's being the fly.