I will say this:
On Siamese Dream & Mellon Collie and the Infinite Sadness, The Smashing Pumpkins mixed alternative rock with hard rock, heavy metal, shoegaze, progressive rock, dream pop & neo-psychedelia. "Quiet", "Hummer", 'Geek U.S.A.", "Jellybelly" & "Bodies" demonstrated that The Smashing Pumpkins could make extremely, crushingly heavy songs that could smash a mountain, and "Spaceboy", "Luna", "Tonight, Tonight", "Cupid de Locke" & "Galapagos" show that The Smashing Pumpkins could make gentle, delicate songs that were gorgeous and incredibly intimate.
Also, Billy Corgan and James Iha were incredible guitarists, and Jimmy Chamberlin's drumming was powerful, propulsive and jazzy. Billy Corgan's vocals aren't the best on a technical level, but it's that rough, untamed voice that makes The Smashing Pumpkins into who they are.
Also, The Smashing Pumpkins were influenced by Black Sabbath, My Bloody Valentine, Husker Du & The Cure. You have to love that.