Mercaptanes are pretty much all smelly (less so as they get large and less volatile). So are arsines and other fun reactive chemicals although I think mercaptanes are so smelly to us because they are common byproducts of putrefaction and this is the case of evolution telling proto-man that eating this particular smelly animal carcass would be a jolly bad idea. Ditto the aptly named putrescine and cadaverine (and many of the long-chain fishy amines in general). Those who evolved to recognize the smell as 'bad' lived, the others followed the cold merciless miracle of natural selection. Makes one wonder about lutefisk, durian fruit, and many of the nastier cheeses...

The headaches are real, though. Mine get bad enough to qualify as migraines.

Artem