Its cultural impact is undeniable and is generally positive. It depends on how you define valuable. It's pretty subjective when describing a video game.
By valuation and number of copies, it sold for more than any game. It defined an entire genre. It's culturally relevant a decade on. There's almost no metric that you can't define it as the most valuable.
Is it though? Yes, it did sell the most copies of any game ever, but how are you justifying to call it "the most valuable"?