Hi
Tirak69 is spot on with his comments. I recommend High Class. Go to Emmanuelle, as you stand at the foot of the stair-case adorned on each side by crouching lions, you look to your right into a small lane, walk down this lane and look left of this lane...you will see High Class. High Class has two groups of ladies (traditional massage and sex massage) on the left and right inside the glass tank respectively. You can ask the papa san to explain the numbers, the 'V' on their number badges, etc. I think High Class has bathrooms in their massage rooms unlike Nadia.
Barbara at Copacabana in my personal opinion has less quality girls but sometimes the variety can stun me although I think in all the times I went there for an afternoon coffee at 1-4pm, I see nothing or buffalos only.
I think you can also try Utopia. Check
www.bangkoktonight.com for the Ratchada map (not sure if it shows Utopia). Ask for the album where you choose and they call the girl over the phone. This one may have a better bet because the girls may be at home but they are likely to take 45 minutes to come to you because of their make-up time and travel time (although most of them live in Ratchada/Suthisan area).
enjoy.