Triangles have star shapes when there's snow on the ground.
But Square is the most classic, so I'm going to go with that.
Square is my second favorite and what I have in my town. When I was picking my map, I was going to be good with circle or square, but reset if it had triangle.C'mon, no one like squares?
I don't care so much for my grass' shape to be honest, but I have the circle grass in my second town and I find it really cool. I have the triangle grass in my main town, it looks okay.