Sukhumvit Road is the best address in Bangkok when you are looking for massage with happy ending. For general information about happy ending massage, click HERE.
Almost every B2B parlour have happy ending massage on their menu, and sessions last from 30 minutes and up. The massage itself may be of variable quality, but the finish will certainly make you happy.
The map further down on this page shows areas where you will find salons that are most likely to offer happy ending massage. Yellow hearts are salons visited by the author; they are listed below.