Everywhere. The louder the better. If by baby you mean a newborn baby, they have a biological response whereby if you take them somewhere loud they will fall asleep. I take my newborn wherever i want. I just put her in a sling and she falls asleep there and never makes a sound all through dinner. My son and the children of my friends are all the same way. They can also be fed while they are in the sling.
For an older child, well, it depends on the child. I would still go somewhere loud so that if they cry they don't bother anyone and where service is quick so that we're not sitting around too long in the restaurent. Chinese is perfect for that. Again, places where service is quick.
As for a mobile child, i do not take them to eat out unless i am able to make sure they stay seated so they don't get in the way of the servers (it is very dangerous for them if someone drops a plate of hot food on them).