You never listened to The Pumpkins during the 90's? That was definitely the best time to do it though most of it probably holds up well even without the nostalgia factor. Easy to forget how popular they were- in terms of 90's rock, they were probably only 2nd after Nirvana.
Anyway despite his douchey qualities, Billy's definitely a talented songwriter and musician and it's pretty amazing that he was able to pull off something as ambitious as "Mellon Collie" as well as he did. His voice takes some getting used to (alternates between wimpy coos and ugly whines) and some of his lyrics are truly embarrassing but in general, those early albums are all pretty solid. Rarities comp "Pisces Iscariot" is actually my favorite but "Siamese Dream" is nearly as good and their most popular so you should probably start there.