Chatuchak Weekend Market (Sat-Sun, 8,000+ stalls) is iconic but daunting. Asiatique (riverside) and JJ Green are easier.
Chatuchak opens 9 AM – 6 PM Sat-Sun. Bring water; the market is mostly uncovered.
For evening shopping: Asiatique opens 17:00 – 24:00 daily. Easier than Chatuchak.