I've never even tried it with Amaretto myself, but I'm glad it worked out! I bet that would be good.
We went through about a gallon and a half of store-bought eggnog this weekend. The gallon was from a local creamery, and was really good. The half was from Target, but not bad either. I had mine with pretty good dark rum. The kids had theirs plain (of course).
All in all, a good experience, except:
I gained three pounds. That is a BIG eggnog downside.
I think next I will try making my own, possibly with low-fat or even fat-free milk.