I think it really depends on where you are at in life and what you can afford. If you have to money to buy (new or used) or lease, you should definitely buy.
When you buy, the warranties are actually incredibly great. So far for one year after buying a new car I've had two flat tires and all my oil changes covered, and I've got at least another 7-10 years on my warranty (not fully sure but it's in that area). Plus it's new so, the reliability in general is good. When you buy used, you would want to get something somewhat new, but that doesn't typically come with great warranty, so by the time you add all that, it's the price of a new car.
Perhaps you can buy an older used car that won't require much maintenance and you can do yourself if you are used to it and can pick out a great one, especially if the money is a bit of an issue at the time.
Leasing can be interesting but like someone mentioned, it's a bit more to lease and never "own" and there are a lot more contingencies to lease than meets the eye.