The smell of pink Bazooka bubblegum makes my jaw tighten up and I start salivating.
There is a specific mildewy smell in a lot of old buildings in Bangkok. It’s particularly prevalent in old government buildings but also places like the Alliance Francaise. I’ve always referred to the scent as “Bangkok Whorehouse,” because it does seem to be in some of the older bars too. I think it must be the specific cleaning products they use.
Play-Doh! I love the smell.
Napalm in the morning.
Here’s an old thread from 2004. The very second thread I ever started on the SDMB.
Not a pleasant memory, or a pleasant smell, but moth balls take me back. My mom had moth balls in every closet, drawer, and what seemed like everywhere. As she got older (and crazier), I think she stepped up her usage of the vile things even more. Anything she brought over to my house reeked of that smell, and had to be quarantined until it aired out. I truly hated that smell!
Much to my horror, though, I ended up buying my own box of moth balls a few summers ago. I’ve never (and never will) use them in the house, but they are great for keeping flies away from my trash cans (outside) during the summer. Just toss a couple into the bottom of the roll cart each week after it gets emptied, and no flies! That one box has lasted me for what seems like forever, and as long as I keep the box sealed tight in a ziploc bag, I never have to deal with the smell permeating my house.
The smell of an operating steam locomotive: burning coal, hot oil, metal.
The sulphurous smell of fireworks.
The smell of the garage at my parent’s place. Like Wesley Clark, I have no idea how to characterize it, but I’d be able to identify it instantly.
The vaguely ozony smell of early video game parlors.
The smell of old oil and dust in a mini video game parlor attached to a convenience store.
The smell of diesel fumes reminds me of the anticipation of riding the bus downtown, back when downtown was an exciting place.
Night blooming Jasmine in San Diego.
When I was a kid (1950’s) that aroma used to drive me insane. How could anything possibly smell so wonderful yet taste like petrochemicals at the same time? Yes, I tried. Once.
Two-stoke motorcycles burning bean oil. Not a lot of that going on too often.
There is a smell I can’t target, but I can only label as “Federal.”
It’s a combination of dust; it’s age; it’s must; it’s old hydraulic fluid; it’s aged oak and pine timbers on crates and pallets; it’s the smell of Xerographic solutions; it’s diesel fuel; it’s humidity bringing in pollen; it’s aging cellophane; it’s hermetically sealed water; it’s years of gentle human perspiration; it’s damp concrete indoors. . .
It’s the subtle combination of all of these ingredients in some of the places I visit that strike your nose as the “Federal” smell. 'This place has been here, and is still here for a purpose, and it smells like it.
Tripler
There is no other mixture like each individual location, but they each bring me back to one location.
The bubblegum cardboard smell from opening a wax pack of baseball cards.
The plastic chemically smell from unwrapping a newly purchased cassette tape of your favorite artist.
Sometimes I’ll open some printed material, and get a whiff that takes me back to the smell Super Nintendo game manuals had when they were brand new and you first cracked them open. I imagine that smell is to me what “new car smell” is to some.
Then you’re sure to lovethis.
I love the smell of a barn, most especially on a rainy day. Reminds me of times spent on my grandparents’ farms.
Also, the smell of turpentine immediately takes me back to times spent sitting on my father’s knee as he cut stones in his little hobby room. I learned a lot of geology during those sessions.
I loathe the smell of Brut cologne, but every time I catch a whiff, I feel like I should climb in the back of someone’s car. Good times. 
The smell of citronella fly spray used on horses takes me right back to being twelve and my horse-crazy youth in dusty summer California.
The smell of wet wool mittens drying on a woodfire stove.
There is a smell certain electrical appliances, especially older ones from the 1950s or 60s have. I notice it especially with hand mixers, but also sometimes with electric knives. It has an almost vanilla smell, kind of sweet but definitely mechanical. (And I can still smell this smell on a mixmaster my aunt has had since she got married in 1965, it isn’t a new plastic smell or anything life that)
My son has the olfactory equivalent to being a super taster. He has a pencil box that he opened and said that it smelled of “his old schol” I thought he meant the one he left when we moved in 202 but it was the one he went to for half a year in 2008-2009. (He was 5) He identifed this smell in 2015. He was really preturbed when I switched from using Palmolive dish soap to Dawn, he said our kitchen didn’t smell like home anymore.
Hmmm, while it does smell wonderful, but to me it also smells like petrochemicals, but I admit I’m not sure if I came to this conclusion before or after I found out about the chemicals in it.
yup
coffee
gasoline, especially the leaded kind that I cant smell anymore
the smell at the lake when boats are being filled with fuel with the noise of the water!
cedar
pine trees in the cabins area in lake michigan camping parks, old tents smell
there are soooo many of them and the smell comes out of no where as some days progress and takes me back…so easily.