Overrated: Almost every house since 1995, except Histoires des Parfums and MPG. Most of the half-baked Bonds and half of the repetitive Lutens and Fords could disappear and we wouldn't be much poorer. Chanel's exclusive fumes are well-conceived but have terrible lasting power. Guerlains are harsh and ornery except for the parfums. EL still purveys quality in its backlist but the recent offerings have been either uninspired (Sensuous) or undermarketed (the private collection fragrances). Killians are waaay overpriced; half miss the mark. ELDO is creative but wildly uneven. Have no use for Goutals, Artisan or the pretentious Le Labo. Givenchy has suffered a lobotomy. This is not to say that each doesn't have some nice offerings; they all do. They just need to edit the lines and deliver some real value for the inflated price tags.
Underrated: The now discontinued Rochas line and the older, discontinued Fendis.