Best-Written Campaign Setting?

[Azuresun]

I *hated* the commentary in Xanathar's guide. It felt like it was coming from an 8 year old, not an ancient super-genius.

I quite liked it, because if you think about it, the Xanathar is an unstable and trigger-happy narcissist who can instantly kill anyone who displeases him. So of course nobody is going to tell him his jokes are lame, they're going to laugh and laugh for minutes on end (because nobody wants to be noted as the one who stopped laughing first).