Pigeon
Pigeons have achieved global cultural saturation without any organised public relations effort. They appear in religious texts (Noah's dove), military honours (the Dickin Medal), and modern art (Banksy's installations). They occupy every major city's public squares, demanding nothing yet receiving tribute in the form of breadcrumbs from millions daily.
The pigeon's social strategy involves passive ubiquity: be everywhere, demand nothing, accept everything. This approach has proven more durable than any galactic senate.
Yoda
Yoda trained generations of Jedi Knights, influenced galactic politics, and became a legendary figure across countless star systems. His teachings reached Luke Skywalker and, through him, an entirely new generation of Force users. He appeared as a Force ghost, suggesting influence extending beyond physical death.
However, the Jedi Order he led ultimately collapsed, his students either turned to darkness or died, and his most famous pupil operated largely on instinct rather than teaching. The return on investment appears questionable.
VERDICT
Despite institutional failures, Yoda's direct influence on galactic events and continued posthumous guidance gives him the edge in measurable social impact. Pigeons influence no one deliberately.