I agree with @WestRiverrat and @dpworkin . Both made points I thought of when I read this question: How a parent responds to the “terrible twos” largely determines how long the behavior will persist, and also that a child who is spoiled and used to getting his or her own way will already exhibit terrible behaviors before turning two. I used to work with toddlers, and most of them were not yet two when they came into my classroom. Even then, it was clear which ones controlled Mom and Dad.
When a child of any age pushes limits, consistent, loving enforcement of the rules along with a healthy dose of personal responsibility will usually curb the problem. Some kids are easier than others, and some will put up a huge fight before admitting defeat. When my youngest was two, he decided he should have candy for breakfast. For a week straight he threw a fit every morning when I said no. He finally gave up on that and instead asked for ice cream. Another week of being intensely angry each morning went by before he finally decided to eat a normal breakfast without any drama. I was shocked at how long he kept it up even though we never caved in. Our two older kids would never have lasted one morning, let alone seven. He’s still a “drama queen” but not nearly so often as when he was younger and he gets over his frustrations much more quickly.
That said, in my experience it is the threes you really have to watch out for. I love, love, love two year olds!