I grew up around two very different industries and the smells around them remain pleasant to me. The first was the timber/lumber industry and the smell of freshly cut lumber or logs makes me want to stop and just breathe it in. The smell of red fir is my favorite. The other industry was the petrochemical industry and I kind of like the smell of sulfur! It is one of those nostalgic odors for me.
I really like the smell of elk. Gunpowder; single base or double base.
From my motocross days, the smell of two-stroke exhaust; especially if burning Bardahl VBA. Hoppes #9 and G96 gun treatment.
Sadly, as I age, my sense of smell is diminishing and I feel I am missing out on a lot. GD