Tim VanMilligan continues his series on using a wind tunnel (12" open circuit, Eiffel type) at the Air Force Academy: Newsletter #346. His article explains the whole experiment and has lots of photos. The chart below summarizes his results. This clearly shows which shape is best for your typical modroc. The results will change as you approach and cross Mach. This also agrees with other published sources. But it's so cool that he got to confirm the results with professional-grade equipment.