It depends on which city you're going to be living in. If you're living in LA, you need a car, unless you have a chauffeur with his own car. I would want a car in general, though. You can go where you want when you want instead of waiting on bus schedules, you can go out of town if you feel like it, and plus if you want to go somewhere and come home late you'll be safer in your own car than you would going through public transportation late at night. At least I assume, the only time I've ever taken public transportation besides a schoolbus was when I was on vacation in new york. Frankly, I would never want to be without a car, unless I was living in new york and a parking spot cost more than an apartment most other places.
Then again, I'm american. Life without a car isn't really something I ever considered. I went to a pretty big high school, 1600 people, and only knew two people of driving age who didn't have cars, and they had weird parents and no licenses. I, and most of my friends, lived in big neighborhoods where you needed a car to get to anything outside (you couldn't walk to a grocery store). But, overall, I'd say a car.