Congee is indeed excellent food. I used to view it as food for the sick and the elderly, but I've now have a newfound appreciation for it. Chinese medicine views congee was "medical food". So it goes, congee is good for cleaning the "bad stuff" out of the bowels. What that means I don't know, but it seems to be good for a complaining stomach. I don't have too much to add to Jinmyo's excellent writeup, just a few seasoning suggestions. Congee has almost infinite possibilities, and every person likes it differently. Here's my preferences.

Plain Congee - Add a pinch of salt. Also, dip crackers in it, preferably with seasame seeds. Not Ritz crackers, the regular kind. That adds a salty taste to the congee, and it also makes the crackers taste nice.

Chicken + Scallions - Shred the grilled chicken and toss it in with the scallions. Add ginger if it fancies your tastebuds.

Abalone + whatever - Expensive, but very tasty. Abalone is a magical ingredient. It makes anything taste good.

Salted Pork + Salty Egg - Yes, I like my congee a bit salty. Don't chop the pork, leave it in smallish chunks. Let it soak in the congee. This is nice.

Thousand Year Egg + whatever - This one is good. Thousand year egg goes very well with congee. Dump whatever else in, as long as it doesn't make it taste wacky. BTW, wait until the egg is soft before eating.

There are plenty more I've tried, but these are my standard ingredients. If you want to try others, go to Chinatown early morning and try the restaurant ones. There are usually thousands of variations for you to choose from. You can eat those with Chinese Crullers.

In fact, the traditional Chinese breakfast consists of congee, bread stick, and perhaps some tea. Good stuff. Go try it out in Chinatown, then take a walk. Nice way to spend a morning. I recommend Toronto Chinatown. That place rocks. I have never been to San Francisco's Chinatown, but I would like to visit.