Yaowarat, Bangkok's Chinatown, is a good place to head to for a wonderful dining experience. The area houses some of the best and most expensive Chinese restaurants in the city, along with many of the best and cheapest food stalls, especially at night.
The restaurants mostly specialise in Southern Chinese (Cantonese) cooking, with noodles, seafood and, at lunchtime, dim sum dominating the menus. Large (and pricey!) restaurants line the bustling Yaowarat Road, but venturing into the little 'sois' (streets) or lanes will lead you to much cheaper yet equally enjoyable establishments.
At night, the streets light up with blaring neon signs. Ad hoc seafood stalls line the sidewalks, drawing such crowds that late-comers have to wait for seats.
Close by is also Pahurat, if you're in the mood for Indian food. But, if the array of sights and smells is a bit too overwhelming for you, head over to the Old Siam Shopping Centre, where you will find more tourist-friendly, Western and Thai restaurants, along with the odd fast food outlet.