For a light flavor punching fish soup head down to the fish soup store at Tai Sun Eating House. It is not hard to find this small shop amidst other stores as this one has the longest queue.
Ordered the small fish soup and I have to say it was really shiok. The broth was light and full of flavor and the fish was not smelly and cooked perfectly.

Pro Tip: Add their deep fried fish eggs for an amazing crunch and full of flavor for just 50c extra.