The deceptions and intrigues involved in the Last Battle were written in such a way that they could be digested by even the youngest readers, without losing their importance. I appreciate CS Lewis for that as I was very young when I first read it. The older i got, the more I was able to get, but it was because I knew more and had more context to compare it to. So as far as end times/apocalyptic literature goes, Last Battle is top tier and handles a potentially devastatingly frightening subject with its proper respect, but gently.
However, it was the great throne of judgment which has stuck with me the most all these years. Every beast standing before Aslan and just one look into His eyes is enough to condemn or reward. I found that so powerful.
With the exception of "Further up, further in" which still gives me goosebumps, I found the judgment scene most poignant, on that day there will be no more excuses, no petitions, no arguments that will work. He knows and you know too. He will either say "Well done my good and faithful servant", or "I never knew you, depart from Me you workers of iniquity". That's it.