In addition to the crepes I recommend the croque madame. We ate those for lunch every day in Paris and it never got old. I second the "hot chocolate" as well, if the weather is not too warm. I expected to hate Paris, (my 7 year old picked the destination), but I ended up having a great time. Learn a few French phrases as the locals will appreciate it no matter how badly you butcher it. French people are cool, I thought people in London were the major assholes for no reason.