That question is so vague - you know many entries would say AFK or OMG xD
Anyway, my all time favorite Nov Monthly Collectible would be the Autumn Glory, from 2007. Honestly, i love this item because i love fall. The pose where leaves fall is perfect, it's basically the exact pose as the Aphrodite item that has pink roses falling and same with winter rose.
I enjoy using it with multiple avi - looks, and attempting to own a 2nd pair. The scarf is cute and vibrant with colors and the mug is awesome. I haven't found another item that can have a smoke or steam like fog come out of the mug because its hot chocolate or coffee. besides a NUT full of glory right? yeah i don't know - don't pay attention to me. But yeah - i really like Autumn Glory, Nov 2007.