What CB channel is the best to monitor?

Question

So I can hear people chatting? If it matters I do most of my driving in Houston.

Answer 1

Most of the truckers use 19 universally and will use other channels if part of a gang of trucks or as part of a company crew.

Outside the US and Canada, 27.555 is pretty popular for Dx

Answer 2

Well you can hear a lot of truckers talk on Channel 10, 17 19 and 21 for traveling on highways and interstates.  

If you want to listen to emergencies then channel 9 is reserved for emergency communication.

Other than that you should be able to go to any of the 40 channels to hear someone chatting.  Clarity of talk may depend on the quality of antenna you have.