If I lived where there was fast, clean and reliable public transportation (like Seattle), I would sell my car in a minute! No payments, no insurance, no maintenance, no gold (ooops, meant gas, lol).... I would have $700-800 more dollars in my pocket every month. I've always been tired of being "car-poor" so to speak.
Matters where you live and what you do. Some places have such good public transport, people don't need cars. Others, you need a car to get anything done reasonably in a day. If you want to work at night, late, you need a car.
You can live without a car, but it'll be very difficult to travel by bus or by someone else driving you. Taking a car is way more smart than having to take public transportation. Plus, it won't be good if you have an emergency and you need to drive somewhere. There is lots of cons when it comes to not owning a car.