Never let a taxi driver suggest for you to see something or go somewhere. They will most likely take you to a place where they get a kickback. Ive heard stories of people being taken to shops with outrageous prices, restaurants that are lesser quality, or even strip clubs for a free "drink" then the second drink costs like $100, but you never see the menu. There are a lot of crooks out there who are not bad people, but just trying to make a buck. Tourists are an easy target for them.
What are some other horror stories that people have had? This is a great and informative thread!