Lowest polygon count model printed in ABS at 20% scale, about 5cm high.
Not an easy print due to lack of good contact surfaces and the many thin and pointy things. Printing the helm upside down with supports seems the most reasonable approach. It took me 4 attempts, eventually I used a thin plus-shaped support, created by subtracting objects in Blender and leaving a spacing slightly thicker than one print layer. This finally ensured that the object was well-anchored and didn't curl up too much.
(Before you ask: Bart was not printed, it was a gadget I had lying around that happened to have the right size.)