Generally, daily disposables are the most popular choices. They are easy to care for as you toss them out every day, and are also great for glasses-wearers who just want to wear a pair occasionally, such as to a date or during sports. Daily contact lenses greatly reduce the risk of damage to your eyes from incorrect care.
Longer wear lenses offer some cost-savings compared to dailies, and give you the advantage of being able to take them in and out throughout the day, e.g. when you want to take them off when working.
The biggest downside is that they need the utmost care every time you wear them, which can be a chore when you come home after a long day's work. You also have to be diligent in making sure you change them on time. If you are prone to losing lenses, monthly lenses also tend to be very expensive to lose.