I used to stay in Alexandra area and my dad would bring us to Alexandra Village Market for Rui Ji (瑞记) Congee. After we shifted house, I will occasionally drop by to eat their congee.
I love their raw sliced fish, it is marinated with their secret recipe. It is very fresh and yummy. They start selling at 7.30am and will finish selling by 11am. Every morning you will see people queuing up. Sometime I have to wait for 30 mins before it is my turn. I would say it is worth the time queuing.