Question:
Like many of you, I have been disappointed several times as well, by department store brands, and expensive Houses. The ones which failed to satisfy (after hype) were:
Angel
Chanel - all of them except No.19
Lolita Lempicka
Hypnose
Narcisco Rodriguez For Her
Miss Dior
Salvadore Dali
To name a few!

Answer:
I've had many disappointments, so I'll name a few.
Bond No 9 Fashion Avenue: This is perhaps my favorite scent by them in terms of just how it smells in the bottle. But it only lasts a couple of hours on me, so I consider it a waste of money because Bond is very expensive. I should have played around with some samples first. Dodgy bottle maybe?
Burberry Brit Red: Smells great, but I get ten minutes from it at best.
Chritiane Celle Calypso Violette: I liked it a lot in the shop, and now I think it lacks depth.
Creed Love in White: Smells like wet dog on me, but I love how it smells in the sample tube.