LG G Watch Urbane
Of course, all of LG's smartwatch options will work amazingly well with the LG G5, and that includes the newest LG G Watch Urbane. It's one of the best looking Android Wear smartwatches available today and was recently updated to Wear 2.0 by Google. Another option is the new LG Watch Style and Sport.
The LG G Watch Urbane has a big 46mm face and comes in Gold or Silver for $249.