Perfumes and perfume oils are my absolute favorite thing in the world--maybe even more than makeup!
I love:
Viktor and Rolf Flowerbomb - it's pretty steeply priced, but I've seriously had people trail me through stores (more than once!) oohing and aahing over my perfume. I'm out of my first bottle, but I'm SO asking for another for Christmas! I've never smelled it on ANYONE else around here...probably because there isn't anywhere to get it within at least 200 miles (except for the internet, which is where I get mine!)
Lolita Lempicka - I'm wearing this today. I love it. It sounds pretty popular from the posts here, but again, I've never smelled it on anyone else. Of course, we just got a Sephora (40 miles away from me), so that may well change now.
BPAL oils. I can't pick just one, but these are the most truly unique and unpopular, and I love so many of them!