If you are out in Bangkok at nighttime and you get hungry: try Nanapan, a “street restaurant” / cookshop between Sukhumvit Soi 5 and Soi 7. Since many years Nanapan has the best Thai food on the Sukhumvit and I love to be there and eat / drink / watch the people.
Nanapan (or Nanapun) is easy to find. You will find Nanapan in the middle between Sukhumvit Soi 5 and Soi 7 and located direct in front of the tailor “Baron´s Fashion”. They start service at midnight. My favorites: Pork with rice and Thai-Basilisk; Fried rice with shrimps and an egg on top.
Try it! I am sure, you will like Nanapan! Everytime I am in Bangkok, I sit there some hours and watch the people passing the cookshop….. unbelievable. Man, Woman, something in between, everything 🙂