Stone Cold Dead- Canadian crime-thriller from 1979 that has all the ingredients to make a sordid classic but the movie runs too long and too slow. You do get a serial sniper, prostitutes, pimps, drug addicts, strippers, lots of street scenes of massage parlors/grindhouses/adult theaters, etc. Definitely worth checking out if it's cheap. My blu was around $10 shipped off of eBay.
Sticking with a similar theme, Gary Sherman's Vice Squad is being released on Blu this summer!