Last year I ran Heroes of the City more-or-less every day for a week in a campaign that spawned a 6000+ word actual play write up. Later this year, the group is getting back together to run Season 2 of that campaign. Suffice to say, I really like this system.
The Bundle of Holding is currently selling the core game and a bunch of PDFs very cheaply (with 10% of your money going to charity) so now is the perfect time to pick up a copy for yourself.
You can find the Heroes of the City setting (along with useful advanced rules) in the Blood on the Snow book, so you may will want to beat the threshold price to get that.