I love a MOC that makes you look twice to determine it's scale. This medium assault cruiser by Rancorbait hits all the right proportions with larger bulky surfaces to smaller greebly bits. I think it's the careful use of a couple minifigure hands that gives it the right amount of small detail in it's silhouette, which is important for establishing scale. And the use of thinner parts like the flags for the front end and the panel creating the intake or docking bay on the side protrusions. Those help break up the chunky surfaces dictated by the thickness of standard bricks.

"Nova" Medium Assault Cruiser