I always had good luck with theeroticreview.com, but have no super-recent experiences to share. I also remember www.michellesescorts.com and www.secretly-yours.com being pretty reliable as agencies.
The days of Tom Cruise ordering SPs from downtown Chicago to his suburban McMansion are long gone. (Risky Business)
These days, it's re-labeled human trafficking rolleyes: ), and I wouldn't be surprised if Chicago PD is getting their share of federal dollars to make busts.