Even before I took up smoking, I liked the smell of cigarette smoke (I often used to place my face over full pub ashtrays (when such things were legal) and inhale deeply the distinct tarry smokey smell, which for some reason I perceived to have a quality of essential 'purity').
Smells I don't like:
Fish that is just beginning to 'turn' (fresh fish no problem, rancid fish likewise, but when it's just beginning to go off ... bleurgh!)
Rotting meat (but that is such a natural reaction that I doubt it qualifies as personal)
Camphor (if I smell even a whiff, it immediately makes me panicky and feel like I'm suffocating)
Tequila (can't explain this, it just provokes an immediate 'no thanks' reaction, which probably did me a favour by making me opt out of tequila sessions at university)
The rank odour that bursts out of a newly-opened packet of salted peanuts (they taste delicious, but my God, that smell)
The smell that you get when you crack open a hard-boiled egg (again delicious, but the initial smell is foul)
Caged mice, rats or other rodents (that all-pervasive reek of piss-soaked wood-shavings makes me want to hurl, it's even perceptible when their 'bedding' has just been changed, and it is often carried on the clothing of the owners of such pets)
Most varieties of air-freshener, particularly Glade's "plug-in" range, which fill the room with a nauseating, cloying and stifling synthetic smell that is meant to resemble flowers, but which bears as close a resemblance to that aroma as a pig does to a duck
Lynx deodorants: Now going out of fashion at last (thank God) but detectable at fifty paces upon whatever spotty young scrote had applied it liberally to his body to increase his chances of pulling. The 'Africa' variety was particularly repellent, possessing a quality not unlike a reheated chicken tikka masala served wrapped in newspaper
Cancer. Some people can smell it, some people can't, and I'm one of the former. It's a hard-to-describe odour, which is overwhelmingly sour in nature but which also possesses top notes of nauseating sweetness. Usually imperceptible (or very faint) in individual cases, unless the condition is advanced in which case it is impossible to ignore. I used to think it was just me, or perhaps some illusion created by my perception of the illness, but I have been assured by nurses who work on cancer wards that it does indeed exist and (when many terminally-advanced patients are gathered together, e.g., in a hospice) can be overpowering. I therefore strongly believe in the contested abilities of cancer-smelling dogs. I used to regard it as a curiosity, but after repeated experiences of the smell, it now provokes a deep sense of personal hopelessness and despair, sometimes so strong that I involuntarily close my eyes and retreat inside myself for a moment or two. If death had a smell, this would be it (I know that dead bodies tend to smell a bit cheesy, I mean the concept of death itself).
Other people's farts, which are rank and offensive, whereas my own are perfectly acceptable and sometimes even pleasant and enjoyable. Why is this such a common experience?