I agree, Harrah's is your best bet especially if you are staying in the French Quarter. If you are looking for the best casinos in the region head over to Gulfport and Biloxi.
I've had the pleasure of four trips to New Orleans this year (mostly for business but one was for my bachelor party

). New Orleans is still one of my favorite places on earth. Granted, crime is much more of an issue post Katrina but don't let that deter you from enjoying the NOLA atmosphere, hospitality, and incredible food. Pre Katrina we would walk from Bourbon Street to Harrah's even late at night but post Katrina I take a cab at night.
I don't know if this is a case of a Harrah's dealer spinning PR but I had one claim the night they reopened the Superdome (Saints vs. Falcons Monday night game) set a record as the largest single night revenue ever for any Harrah's property in the world. I find that hard to believe but I hope the casino and the town continue to recover.
Have fun, be safe, and drink a beer or two or twenty for me.
Oh yeah, I think I have a $5 "We're Back" and $2.50 chip from Harrah's New Orleans. I can dig 'em up and post them if you want.