Finally think I have enough data to contribute something here. I haven't seen as many girls as the other guys here, but hopefully my intel helps at least one person out. Note I'm an Asian guy in my 20's, so my standards may be slightly different, so take everything I say with a grain of salt.
Tier S:
Hana (Sesang): Overall best of the best. Looks early 20's, super PSE, cute face, perfect spinner body, great personality, highly skilled, best BBBJ, high stamina, can't be topped. I've seen her almost 10 times and never been disappointed once.
Tier A+:
Rie (MilknHoney): Prettiest face, nice body, looks like late 20's, super GFE, nice body, really personable, best English, best DFK, very sensual. I would put her Tier S, but she's not as skilled as Hana.
Tier A:
Ravi (TopGirls): Looks late 20's to early 30's. Very pretty face, some may think she's prettier than Rie. She looks more glamorous pretty whereas Rie is more GND pretty. Nice body. Nice personality, but a little business-like. I would put her A+ but she's a a bad kisser; she only pecks. Service not that great, but she is pretty enough to make up for it.
Alice / Rosie (Retired): There was a girl who worked for maybe TopGirls (that was super cute and young, but she didn't say long. Thought I'd add her here in case she ever came back, but that was one of my most memorable sessions ever.
Tier B:
Lyn (Sunny): Looks late 30's or early 40's, but don't let that steer you away, she is very good looking for her age. Known for her DFK but I actually think Rie is a better kisser. Very nice body, maybe a bit too skinny for me. Overall a good experience.
Cami (cakdolls): Looks early 30's, nice athletic build. Pretty-ish face, but doesn't compare to the girls above. Robotic service.
Allie (sexyfunkgirls): Looks late 30's, early 40's. Curvy build, not pretty, but crazy Hana-level service. Some of the best sex I've ever had.
Joy (mykupcake): Looks late 20's, early 30's. Not that pretty, but really nice butt. Robotic service, but for whatever reason she feels the best. I could not last in doggy.
Diva (eukgirls): Looks late 30's. Not pretty, but crazy BBBJ. I would say Hana is better because she knows how to make you finish, but Diva's BBBJ is worth a try. I've never finished into someone's throat before. That was crazy.
No repeats:
Victoria (M): Old, unattractive, unskilled, cig breath, etc.
Rozie (eukgirls): Old, rushy, not attractive.
Melody (eukgirls): Old. Really old.