I have just completed a successful search for a condominium in Bangkok, using Khun Kai from BKK Condos; I was very pleased with my experience. This was the third condo I have rented in Bangkok- BKK Condos was the third company I have used when searching for a condo in Bangkok. I would rate BKK Condos as the best of the companies I have used based on the prompt responses, understanding of my search needs, ability to negotiate with the landlord and attention to detail. 
I came into contact with BKK Condos when I submitted an email request for information for a condo listed online- not only did Kai from BKK Condos show me the unit I was interested in, she showed me 4 other units all within a block of the first unit and within the same price range. Unlike other search agencies, Kai didn't try to push me to other parts of Bangkok to view condo's or waste my time with units that didn't fit my criteria. 

I highly recommend BKK Condos and will use them again in the future. 

Richard