It doesn't matter if it's illegal and immoral, or simply plain weird like licking the plates clean after a skat porno shoot (Instrument i'm looking at you). It just can't be something where you basically do nothing, you have to do something in exchange of money...
I wouldn't mind getting paid to kill people - a contract killer.
The problem with that job is that I think murder would become too routine and boring after awhile.
I also wouldn't mind being a criminal profiler. Behavioral science is something that fascinates me.
I'm planning to take courses in human behaviour analysis when I can, don't know where yet but it has always been a fascinating thing indeed for me aswell. Watching Criminal Minds got me into it even more, but intimidated me at the same time with the insights they have on how criminal minds work.