Now, i'll admit that i do consider others to be better per se, but the beauty and intelligence of this original Toy Story cannot be overstated.
As tensions in the story rise, one of this films crowning achievements begins to surface; its superb characterizations!! Woody is selfish and jealous of Buzz taking the attention away from him, but who isn't!? Potato Head is quick to accuse Woody and slow to forgive him, who isn't? These characters are flawed and have personal insecurities! They are real!
Mix that with genuinely funny moments (which come from the actual situations, as opposed to relying on pop culture reference with tongue firmly in cheek as so many animated movies tend to), witty dialogue ("The word I'm searching for, i can't say."), and beautiful animation and you end up with this pioneering masterpiece in every sense of the word.