The Bad album includes several songs are not only vital to making the album itself stick out, but are also crucial to understanding Mike's legacy. "Smooth Criminal" has to be without a doubt his finest composition, for lyrical content, complex rhythm arrangement, and overall production values. It's one of the greatest songs of the 80's and one of the most unique songs in popular music history you'll ever hear. I also think that as a whole, all songs excluding "I Just Can't Stop Loving You", "Just Good Friends" and maybe "Liberian Girl", are not interchangeable, especially now that we've been exposed to the demos during the that era. Those songs could have been replaced with "Cheater", "Al Capone" (with more polished production), "Streetwalker", "Price Of Fame", and/or "Abortion Papers".
It's interesting because I believe his main weakness as a artist to be song selection. On Off The Wall it's "Girlfriend", on Thriller it's "The Girl Is Mine", on Bad it's the songs above, on Dangerous it's "Heal The World" and "Gone Too Soon" and on HIStory it's "Smile" and "Come Together". All these songs could have and should have been released as stand-alone singles and would've still sold well. It becomes even more apparent when listening to the demos and the unreleased during each era.