As far as highbrow music critics are concerned, Bad is very disjointed and sounds like a collection of unrelated songs (each one had a different writer after all), but it’s one of his more popular albums. After Dangerous, everything tapered off in popularity, but his first four albums are very well known.
Off the Wall is genre-locked in disco, although it’s easily among the best of the genre. Thriller is excellent, but very overhyped; some of the love songs are incredibly cheesy. Dangerous has the same corniness but more from him trying to do social commentary tracks (“Heal the World” is the most early 90s song ever written. That’s not a compliment.)
Shoot, this is turning into a critique of his whole career... uh, to answer your question I’d say it’s a toss up between Thriller and Bad as to which is more overrated. Probably Thriller, since it’s been mythologized over the years and is now considered almost untouchable among fans and non-fans alike.