One of the best things about my workplace is that Sin City Thai is right around the corner. My lunch break has never been the same since discovering it.
Sin City Thai puts other Thai restaurants to shame. They have hands down the best curry in Vegas that I've ever tried (especially the Panang!) and their other dishes are also excellent. I've been Thailand and the food here is as good or even better as anywhere else.
It can get a little busy during the lunch rush, but that's just because the place is so awesome.
Lin and his crew are awesome too! They always greet us and are super friendly. If you're looking for a good thai restaurant in Vegas, check this place out!