This one surprised me!
I'd heard vetiver was a great base note, but I was sceptical because when I smelt testers in shops it really wasn't appealing. But I took the plunge and bought some, and it blew me away! It really does add amazing depth to your blends. Just avoid spilling any on your fingers if you don't want to smell like a musty campfire for days (don't ask me how I know this).