I love anything peanut sauce, and Cuisine Bangkok's still is the best in the city. Also, Garlic Pepper Squid. Green curry chicken. I like to get spicy or extra spicy and just pick out the hot peppers, putting them aside (it's too hot with the peppers, but on medium or mild I feel that the rice and veggies don't get enough flavor). Spring rolls are pretty great too.
I tend to stick to veggies, seafood and tofu. The quality of the chicken and the beef are just OK, not fantastic. Squid and shrimp are pretty darn good though.