How do you figure it is the "greatest" or "smartest"? The writing system is probably the most logical and phonetically accurate in the world if that's what you mean, as far as the language itself goes it can be terribly vague and confusing at times and bogged down with hierarchical honorifics.
For example: The subject is usually dropped form the sentence, so "가요" ("Ga-yo" meaning "go") could be interpreted as "I go," "You go," "He goes," etc. depending on the context, and "가다" (Ga-da) "가" (Ga), "가요" (Ga-yo), "갑니다" (Gam-ni-da) all have equivalent meanings ("Go") but conjugated according to social hierarchy and context (ie. if the listener older, younger, your boss, your employee, etc.)
It's definitely a very different language than English and it's challenging to learn, and it starts making sense once you've studied enough, but I would hesitate to claim any language is "better" or "smarter" than any others.