There is a restaurant with no English sign on Thanon Ratchadamnoen, a few minutes walk towards Sanam Chan from the Chedi. Transliterated the name is roughly Ratchaphreuk. If heading towards Sanam Chan it is on the left, and is recognisable by it's plastic table and chairs in a comfortable beer garden. Sometimes the place has karaoke. The food is good traditional Thai, but you will be tested on your knowledge of Thai cuisine as there is no English menu.
Any Order
raan a-haan taam sung, rajdamnern rd towards sanamchan palace from chedi, at the far corner of the first block on the right, opposite side of 7-11, if you face towards sanamchan. clean and cheap. they provide english menu with their signature dishes. open daily until midnight to 1am.
Yuer Mai
Rajdamnern rd around 5 mins on the left hand side, opposite side of catholic church. nice and simple thai dishes, air-conditioning.