This depends entirely on your teeth condition, your budget, the results you want and the time you are willing to spend for teeth whitening. It also depends upon the purpose for which you want to whiten your teeth. If your main intention is to make your teeth stain free and shining white then you should go for the professional teeth whitening methods. Such methods might take more time and money, but they are more reliable and effective. If you are just generally worried about the color of your teeth then at-home whitening products are probably right for you. You can use them regularly without any worries of high costs and your teeth would look better over a period of time. If you want to have the best looking teeth for a special occasion like marriage or something, then you should go for faster methods like laser treatment. If you have the time and money, you should always go for a professional treatment after finding the right dentist.
