When I cut into a grapefruit, the grapefruit smell is wonderful. What is your favorite smell?
Roses, new born babies and good black Guinness.
Slan,
D. 
I second roses. I also like the smell of sampaguita, fresh peaches, strawberries, and curry.
Orange blossoms and night-blooming jasmine.
Vanilla, sugar, and nutmeg. Coconut, mango, and grapefruit.
Edited to clarify that these are all the naturally occurring, not artificial, scents.
A 25 year old Highland Park, slightly diluted with Highland spring water. Now that’s a smell to die for 
… and roses, freshly mown grass and watermellons.
roses and anything fishy 
Great topic.
Small waxy flowers – jasmine, alyssum, etc.
Cooking Indian food, the point right after you’ve tossed the whole spices (cloves, cardamom pods, cinnamon sticks) into the hot oil
Bread, right after it’s come out of the oven
A well-hopped beer
Leather.
must … not … say… napalm… in…the … morning
coffee
juniper
nature
my wife’s cooking when I open the door.
cold… …real cold… outside. The pure, crisp lack of smell of -30. we haven’t had it this year. How can I be a proud Minnesotan when it doesn’t even get cold here!
Food smell would be garlic and onions sauteeing. Followed closely by chocolate chip cookies baking.
Other smells - I know they are uber-bad for the environment and people with respiratory problems, but I love the smell of burning leaves in the fall.
Lilacs.
Clean babies.
working in the foods industry for so long, and with BAD flavors (which is actually smell since we only taste five things) for much of that, I’m “ruined” to a lot of the scents people find pleasing.
I can’t stand vanilla. I have a problem with anything cherry/hazelnut flavored (it’s the same compound, smells like cherry at one concentration, hazelnut at another). And artificial flower scents - roses being one of the worst. Same with artificial fruit scents (did you know no one has come up with the perfect strawberry yet? It’s way too complicated).
I tend toward earthy, spicy type things when I pick candles or something. I love the smell of freshly cut hyacinths.
When I was a kid I loved the smell of gasoline. I like the smell of freshly ground coffee. When spring is really on the way there’s a different smell in the are from the winter smell. I like that. I don’t care for roses.
beagles
It is a cold, overcast day here in the heartland, the kind of day that makes you want to stay inside and do some cooking. I peeled the carrots and onions, chopped the cabbage and cut up the chicken breast. I added the wild rice and seasoning, and now my whole apartment has the wonderful smell of chicken soup. I am reminded of sitting around the kitchen table with my father and two brothers, while my mother served up chicken soup for lunch. It sure tasted good on a cold Winter’s day.
mmm…
cut grass (reminds me of summer), the smell when its just rained…which i smell frequently so its good that i like it!,
the smell of glastonbury…the whole town has the most wonderful smell…
*Standing outside the cobblestone in dublin on a spring evening with the smell of the Guinness brewery wafting down.
*A newly tarred road.
*Tea tree.
*Turf fire.
*Burnt out 3-phase motors on weekday evening(overtime for me)!
*New money ink(i work in the currency production centre!)!
*Horses.
*Jackdaws(they smell peculiarly sweet?).
*Wild garlic.
*fishy smell from a creel.
*Fresh meat(i.e a butchers shop!).
*new car.
*fresh sweat from a charming girl.
*extract fans from ouside a boozer when you are walking past.
*trains.(trains and train stations smell the same all over the world).
*Skunkweed from a distance!
*Joop!
Mine have been mentioned already I guess:
new-mown lawn
coffee
rain first hitting sidewalk—I don’t know what makes the smell though
fresh air—I can’t really smell anything in it, that’s why I like it
vanilla
pretty much any fragrant flower
pretty clean human or animal
inside of barns
*oh and old books/librarys!
Hey! Doug said favorite SMELL. Singular. Smell, not smells. He didn’t say make a list of everything you’ve ever smelled in your life that turned you on.
If I’d realized we were going to do THAT, then I would have given you a longer list. Much longer.