Salad King is a great place for a quick and spicy curry or soup. It's ideal for lunch.
These people know spiciness at this place. I like spicy food--very spicy--and the chili rating makes it very easy to pinpoint the level you like.
I can recommend the panang curry and the tom hai gain as being perfectly decent--though nothing is really outstanding. Avoid the green papaya salad: it's entirely lacking in substance, with just some sad papaya and tomatoes.
EDIT:
This place seems to be slowly sliding downhill. The food quality is increasingly mediocre, and every time I go I'm a little less impressed than the last.