This book was the last in the Hot in the City series, and it was definitely better than the last one, but not as good as the first.
So to rank: French Quarter > Key West >> Sin City.
The main character is the last of the Marsh sisters, once again leaving their fiance (this time because he got caught getting service by a bridesmaid). Carrie runs off onto what was going to be her honeymoon to take a vacation, finds a hot guy, and we have non-stop, balls to the wall, hot sex. Plenty of three-somes, voyeurism and shenanigans ensue, and there's a happy ending for all. Fun read, if you like erotica.