To be honest, it's hard to pick a favorite, as they all have their respective strengths. I suppose Siamese Dream wins out for me, being their most consistent album and having some completely great guitar riffs. However, I think all their albums are strong. Mellon Collie is a fun listen, their White Album in a way. Lots of different styles. Adore alternates from laid back to more menacing, nice atmospheres. And I think Machina has a somewhat unique sound, a mix of industrial (slight element,) electronic and their older style. I like them all.