My Very First Warlock was a traveling inventor/armchair demonologist named Tannis Kind who made a pact with a demon when he was a teenager, taught himself how to make magitech, and became basically a traveling coffee machine salesman. He sort of stumbled into an adventuring group that ended up looking for magical artifacts that belonged to the gods, to return them to the gods that had left them lying around a long time ago. He had been betrothed to the Fae King for quite some time prior to the campaign, but left the Feywild and subsequently lost three years of memory because (at least in our campaign) if you leave the Feywild without proper protection against it, you get a memory wipe. Which made for a fun campaign arc when our party had to travel into the Feywild and Tannis was hailed as the king's fiancee and members of the court immediately started trying to either get on his good side or poison him, and he had no idea what was happening. Also one time he made a guy clip through the floor so hard that the guy died.
Currently I play (in 5e) Tannis's brother Peregrine, an anthropologist who accidentally picked up a cursed talking sword that is trying to make him into an evil jock, and (in Shadowrun) Foxtrot Donowitz, a Jewish orc MMA fighter.