As soon as I saw the thread title, my first thoughts were the Lanfear vs Moirean scene in TFOH.
There are so so many in addition to that...
Nynaeve vs Moghedien
Rand and Mat in Rhuidean
Moghedien schooling Liandrin
Siuan puppeteering the Salidar AS
Dumai's Wells
Above all these though I'd...
Book 1: Moiraine
Book 2: Verin
Book 3: Rand
Book 4: Siuan.
Unusual choice perhaps in Siuan but I always found her so easy an enjoyable to read, particularly in TSR after the coup.
TSR is probably my favourite of the first four and probably top 3 for the entire series. Love love love the Aiel, the Rhuidean chapters are definitely some of the best in the entire series. Also this book was the first in which I felt myself liking Mat after being mostly indifferent to him for...
I know a lot of people hate her but I have to say I love Lanfear. This probably comes from TGH when she appears as Selene and that slow figuring out from the reader that she's actually one of the forsaken. Great character.