Like JasonCA, I also opt for the tours that support a local historical society or museum. The Cabildo's tour was wonderful. And my group only had 6, so it was easy for us to manuever the French Quarter. The Cabildo's guides are extensively trained, and John McCurdy was very engaging. If you have more than a day and a special interest in a particular culture, historic period, architecture, or music, then it might be worth it to ask at the 1850 House if a particular guide is scheduled who could match your interest. Take a bottle of water and wear comfie shoes, you are in for a treat.