It depends what the rules are. Simply a pickup joint, or can it be a venue frequented by non-pros as well?
I know of dozens of places where literally hundreds of girls are available, but not all are as open thinking as the Del Rey, which attracts nothing but mongers and prostitutes.
The majority in Asia tend to be where lots of working girls are available, but normal girls still frequent the places.
Blok M is honestly, probably the best freelance complex in the world. The best mix of working girls, semi pros, non pros, regular people, keeps you on your toes a bit more, but in no way could you ever go home alone.
Orchard Tower and LA Cafe are other top notch spots, but the scene gets more repetitive then Blok M