Rystic
Turtle Wizard
The promotions granted by a high crime-rate eluded me though. I found a ranger with some elemental or magic resistance once, but that was about it. Since there is no way to monitor crime rates (I think?) this makes it a bit hard to test, but the overall feel was that the impact was so small it was negligeabel. EDIT: I also got a Nyxkin with Hidden Nationality.
I'd really like to address this. There is a way to monitor crime rates, although it's very out of place. If you mouse over the city-bar, you'll get all kinds of information; crime rates are at the bottom. As for crime-related promotions, they work like this: every city has a potential number of promotions and a maximum number of promotions. The potential number equals the city's crime rate divided by 10. The maximum number equals the city's population divided by 5. When a unit is built, a random number is generated from 0 to the potential number. Each of these have rougly a 50% chance to bestow a promotion, with the odds decreasing as each new one is added. When this number runs out, or when it adds enough to equal the maximum, promotions stop being added. So a city with population < 5 will never give out promotions.
Aeron's Bounty, available at Guilds, increases the maximum number of promotions in its city by 1. It also gives stronger promotions.