I think easily, hands down, my favorite smell is that of a camp-fire/bon-fire/wood fueled fire.
It instantly transports me to a feeling of "damn, ok, stop, drop and relax".
I love it when some of my customers approach the counter and their thick woolen overshirts smell of woodsmoke. I always comment to the positive.
I have been lucky enough to find an incense that does a good job of capturing that wonderful scent:
This incense is awesome.
Some of the local asian markets carry it, but I've had better luck ordering it online.