Help

I've been meaning to ask this for eons and I've just cataloged the new Terry Pratchett Discworld book.

Question for the fantasy readers out there:

Which would be the better series to start Sparky on this Christmas: this one (Discworld), the Xanth series (Piers Anthony), or the Douglas Adams books? Or
another one?

I'm tempted to start him with Terry Pratchett; there are 30 titles in the series, so he would be set for a few months anyway.

He needs to find something to read beside manga and children's books that were too young for him 3 years ago. Thus says his mom, the librarian. huh

Never too early to shop for Xmas.