Bear
Bears have existed for 38 million years and show every indication of continuing for several million more, climate permitting. They have witnessed the rise and fall of countless species, including several early human competitors who presumably discovered that cave paintings of bears were no substitute for bear avoidance strategies.
Their genetic legacy is distributed across eight distinct species, ensuring redundancy should any particular variety succumb to environmental pressures or particularly aggressive photographers.
Mario
Mario's legacy depends entirely upon continued technological infrastructure and cultural relevance. Video game characters face the constant threat of obsolescence - consider the tragic fate of Pac-Man, who now appears primarily in ironic T-shirts worn by people born after his cultural relevance expired.
Nintendo's corporate longevity is impressive, yet corporations are notably more mortal than bears, with an average lifespan of approximately 15 years.
VERDICT
When the last server hosting Mario's adventures finally fails, when the final Nintendo console becomes a curiosity in a museum visited by intelligences we cannot yet imagine, bears will still be fishing salmon from whatever rivers remain. Biological legacy, it transpires, possesses staying power that digital fame cannot match.