It is rare that a quilt gets a WOW from me, but I must say the design and fabric choices such as in Dunster's Log Cabin Diamond Star quilt.
The other thing is when people can take tiny bits of fabric and create an incredible scene, such as people's faces and places that require depth and perception to view, without changing the shape of the patches. One such quilt was a rocky canyon and it was magnificent.
I am no artist. I like my traditional blocks in nice colors and that is my limitation. I don't care to create art, but something that will provide warmth and comfort for the recipient.
I envy many who have real artistic talent in creating their quilt and love to view them, but I don't get the WOW to often for traditional quilts, which I love.