I usually head over to Camay Wok when I'm craving won ton soup. It's in the food court at Royal Centre, so it's usually really busy at lunch time.
My soup of choice is the BBQ pork & won ton soup, with bok choy and a fairly decent portion of pork. It sometimes has some broccoli and carrots in it - I guess it depends on the chef, as it's not always the same.
Their prices have recently gone up, but they are on par with all the other food court places so it's tough to complain. For a big bowl of the BBQ Pork & Won Ton soup, it's now $7 - I'm usually full after I'm done eating, so I guess it's worth the money. Service is decent, but they are not very friendly - they rarely smile. I guess they are just busy and trying to serve everyone efficiently, so no complaints.