Irn Bru Cap
Other soda-bottles just replicate the logo from the side of the bottle on the cap, if they design anything for the cap at all. But you can tell this logo was made just for a cap; the arrows even tell you how to open it. Compared to any other one-color logo on a soda bottle lid, it is indeed phenomenal.
(Unfortunately, even with great design, a bottle of Irn Bru does not taste as good as Dr. Pepper.)