Chat Thai is famous and popular. It's since expanded but this was the original venue that I remembered with massive queues outside. The customer service is a bit varied but the food has been nice when I've been there. There's a few other thai options though worth considering in the area
My least favourite Chat Thai location as they are not really one for customer service or care if you're actually enjoying your meal. I only went here once, endured a long wait for a table and was given a meal which was so extremely packed which chilies that I could not even taste the dish. I probably should add, I'm usually the kind of person who asks for more chilies normally, but this was just something else. It wasn't edible. When noting this to the waiter, it was shrugged offread more
If you can book then please do it because this place is loved by everyone! If you go at the wrong time then you risk queuing up but be rest assured its worth the wait. The food here is authentic and full of flavours and delicious aromas. Service is good and make sure you get the pad thai !