Faces of Bangkok.
The Skytrain will even take you all the way to Mo Chit where the 8000 stalls of Chatuchak weekend market spread out in a medina-like labyrinth. Chatuchak (abbreviated to “JJ’s” by those who know it well: it used to be spelled “Jatujak” in English) has changed its spots in recent years. Once an Asian flea market, it has been infiltrated recently by local talent trained in New York and London and the elite academies of Bangkok; even the humble orchid vendors have learned to cultivate exotic varieties not much seen in Thailand until recently (the magnificent blooms, often cunningly supported by hidden wires, have a reputation for dying young without issue, however).
Enough for one day? If you are still on your feet, there are any number of shops and buildings accessible from the frenetic and hip Siam junction, including a Marks & Spencer and the amazing MBK building: not so much a department store, more a multi-story facade for a vertical shanty town of retail booths which sell anything from computer parts to SIM cards, to clothes, to travel gear, to gold chains, to Thai fast food.
Most likely, though, you are here to cram as much fun as possible into your precious annual vacation. No doubt you will be off to the islands and beaches in a day or so (much of Phuket is still being rebuilt after the tsunami, but Ko Pangan, Ko Tao, Ko Samui and the almost unspoiled Ko Chang were not affected and remain as welcoming as ever), so how to celebrate the first days of freedom from the humdrum?