I've always had a very acute sense of smell, and while it sometimes deserts me for colds and whatnot, it's been pretty constant throughout my life. I've also become pretty good at identifying things by smell. Extra Gum, for example, I can pick out of a crowded restaurant. I can also smell the difference between diet and regular sodas most of the time.
When I was in the 8th grade, we dissected fetal pigs in biology. They were packaged in a formalin solution, which seems to be a aqueous solution of formaldehyde. It has a very distinctive smell, and I've been smelling it all night.
I work in a hotel, and Meth cooks are pretty prevalent in this city. It's not unusual for them to set up in a hotel or similar place until they get caught or too freaked out to come back. Meth is supposed to smell like cat urine; sort of a high ammonia content. I can't seem to track it down to a particular room though.
What else smells like that?