I'm a buffet fan: "All-You-Can-Eat" is my middle name! My vote for best bargain buffet is the Fortune Hotel's ground floor coffee shop. Located on Ratchadapisek, near the Rama 9 intersection (near all the subway construction).

Both lunch and dinner are about 299++ (comes out to about 360 Baht). A nice selection western, Thai and Asia food (Chinese, Japanese, Indian), plus good salads, fruits, desserts. Also, tea and coffee come free.

It doesn't rival grander buffet spreads (like the ones at the Sheraton Grand Sukhumvit, Sukhothai, Oriental etc.) but I think it's the best value in town and the service is very pleasant.