Dungeon Master's Screen Reincarnated
Detail from Dungeon Master’s Screen Reincarnated. Wizards of the Coast, 2017.
Heroscape: Strategizing
Detail from "Heroscape: Strategizing" by Flickr user Gillian
Dada Scrabble
Detail from "Dada Scrabble" by Flickr user romanlily
Rules:
1. No score-keeping.
2. Making up words is fine, as long as you create interesting definitions for them.
3. Starting new words that do not connect to other words is fine. That can be a good way to occupy unused board space.
It was the most fun I've ever had playing Scrabble, at any rate.
Jeremy's Game
Detail from "Jeremy's Game" by Flickr user phoenixar