Aside from being my favorite album and being critically hailed as easily one of the best albums of the 1990's, Siamese Dream boasts what I think is simply the best cover art of any major-label album.
There was an entire photo shoot done of these two young ladies dressed like fairies which yielded some pretty amazing shots, but this one is the obvious choice for the album cover. One of the predominant themes of the album is a wistful longing for days gone by when things were happier and simpler, making the old photos on which the lyrics are presented in the booklet fitting, and the vintage-looking image on the cover particularly perfect. "Mother weep the years I'm missing, all our time can't be given back" Billy Corgan sings in "Mayonaise", a lyric that neatly sums up the mood of all of Siamese Dream.
Recently, this cover art was brought back to the public's attention when the current bass player for the Smashing Pumpkins, Nicole Fiorentino, claimed to be one of the young ladies in the shot. After a bit of research, however, it was discovered that this wasn't true.