Daedric armor anywhere in the vanilla game?

Nope.

The highest tier of armor anywhere is worn by the Ebony Warrior.

Edit: well one of the Daedric Princes does as well as Dremora.

Thanks Shadow. What if I drop the armor in the middle of a city?

I must admit... I had to read that title and OP three times to understand what was actually being asked. Initially, I was thinking of a location.

Odds are someone will ask to pick it up. If you let them, they won't wear it. It is pretty odd.

I'm surprised too, that no NPCs wear Daedric armor at all.