How do we judge which kind of heatsink is better?

Let's have a look at heatsink structure:

Extrusion (two direction cutting)
Pin fin (four direction cutting)
Ventsink (Global WIN patent)

Structure 3 is better than structure. Structure 2 is better than structure 1.
WHY?

Its heat dissipation surface is the smallest. Heaviest. Biggest air pressure results in least air flow.
Bigger heat dissipation surface. Bigger air pressure results in little air flow.
Biggest heat dissipation surface. Lightest. Smallest air pressure results in smaller air flow