This has become one of my favorite Thai spots in China town. It's open late, I've never had to wait to be seated, the atmosphere is very clean and put together, the staff is always friendly (sometimes there is a language barrier but never had a mix up with my order), and the food is DELICIOUS!! The prices are a bit high but you get a lot of food and I've never been disappointed with the taste or presentation.
The ambiance is great for a little date night or hanging out with friends. If there is live music sometimes it can be a little loud but not too overpowering.
I used to go to a well known spot in the plaza next door but Krung Siam is a more intimate experience without the hassle.
P.s. try the pad Thai..your taste buds will thank me later!
Oh, and a shout out to my favorite sever Tom for always being the best!