The Last Battle (Chronicles of Narnia, #7) - C.S. Lewis, Pauline Baynes "Would it not be better to be dead than to have this horrible fear that Aslan has come and is not like the Aslan we have believed in and longed for?"

One day, a mean, old, nasty ape named Shift spots a lion's skin and forces the obedient, somewhat witless donkey, Puzzle, to wear it and imitate the great Aslan. The ape's deception ends up turning Narnia around, and King Tirian desperately calls out to the children of Narnia (the Pevensie children, Eustace, and Jill) to save them.

I Liked:
In many ways, "The Last Battle" is how "Prince Caspian" should have been written. We start up in Narnia, establishing the crisis (the ape and the fake Aslan), following the King Tirian and then having Eustace and Jill arrive. There was a sense of immediacy, of intensity, of tension that is present, that has you gnawing on your nails, wondering how this will end. The scene where King Tirian is tied up and desperate, thinking of the stories of the past and praying for deliverance was well written and heart-stirring. Not to mention, I feel like I actually got to know and understand King Tirian in a way I never was with Prince Caspian.
I love how all the books are woven together in this final chapter. The Professor is finally revealed as Diggory from "The Magician's Nephew". Other characters from throughout the series return (Reepicheep, Cor, Puddleglum, and more).
The return of Eustace and Jill was great, as each has grown even more (especially Jill, as she is a much better archer--Girl Power!). I felt they retained, for the most part, what they were, but had appropriately grown-up. Other than Diggory and Pollly, they are probably my two favorite characters--they are realistic, they are brave, and they are interesting.
The battles are more intense and not shoved into the background. Even though it's a little odd to have children (maybe tweens?) killing, I did like how the battles weren't blink-and-you-miss-it. Also, the subject matter is very much more mature. A false "god"? The Narnians following this false god? The Narnians denying the real Aslan? Wow! That isn't something you see tackled in a bunch of children's books.
And while I wasn't fond of the entire outcome of Susan, I found Polly's words to be the most poignant (especially as she is technically an old woman who has lived her life and understands what it is to be a 20-something woman):
"She wasted all her school time wanting to be the age she is now, and she'll waste all the rest of her life trying to stay that age. Her whole idea is to race on to the silliest time of one's life as quick as she can and then stop there as long as she can."
Honestly, I think everyone can think of a few people who rush to be at a certain stage at life then desperately try to stay that age forever.

I Didn't Like:
If you don't like spoilers, I'll give you a very brief, vague idea of what I didn't like so you can skip to the overall:
1. Susan's outcome.
2. Apathy to the real world.
SPOILERS FOLLOW (You've been warned!)
1. Peter, Edmund, Lucy, Diggory, Polly, Eustace, and Jill return at the end, but Tirian asks, "Where's Susan?" The children rather glibly respond, "Oh, yeah, Susan? Well, she doesn't believe in it anymore, sorry git. Moving on..."
Susan was always my favorite character. I liked how she was practical and not perfect like Lucy. To see her left out of the joys of Narnia is heart-wrenching, even if it does tell a powerful lesson about maturity and belief. I have to hope that the deaths of her ENTIRE FAMILY end up shaking up her world enough that she believes in Narnia again and becomes reunited with them,
2. All the above get to Narnia because they DIE in a TRAIN WRECK. And what is their thought of dying? "GOODY GOODY!" Seriously, don't you regret not seeing your sister? What about all the others you loved and cared for who didn't also die on the train? I don't care if they go to "heaven", but I think even Aslan/Jesus would be crying over those who weren't there yet.

Dialogue/Sexual Situations/Violence:
Puzzle the donkey is called an "@ss" (I think it's literal, not figurative). Tirian says "da**ation".
Some people interpret the reason that Susan didn't go to Narnia was because she found "sex", as hinted in the lines "nylons, lipstick, and invitations".
This is probably the most violent of all the Narnia books. Eustace is said to explicitly kill a Calormene. The Fake Aslan is responsible for killing dryads and enslaving animals.

Overall:
Finishing the Chronicles of Narnia was bittersweet. This final book is one of the better novels in the series, but at certain points, I found myself grinding my teeth. One thing you can't say is that Lewis left this series wide open and didn't bother to bring closure to his world. But I warn, if you don't like Christian theology hammered into your head, you may want to pass this over.