From a "Power" standpoint I would select Usain Bolt & Michael Johnson.
From a classic sprinter picture it was Henry Carr & Tommie Smith.
Both Carr & Smith had the great lean coming around the curve (many times behind) and their tall figures and long strides would gradually catch their opponents & power past them so smoothly. Classic races, for sure. Wish we had videos.
All 200 Olympic Gold Medal winners !!