Many people who visit Bangkok brag about a custom-made suit that was completed in just a day or two, but the finished product often looks like the rush job that it was. If you want an excellent cut, give the tailor the time he needs, which could be up to a week at a reputable place. One of the best custom tailor shops in Bangkok is Marco Tailor, which sews a suit equal to those on London's Savile Row. It's not cheap, but it's cheaper than what you'd pay in London.
430/33 Siam Sq., Soi 7, Bangkok, 10330, Thailand