Not every motorcycle is created equal. In fact, there are a number of different types of motorcycles. The one that is right for you depends on what kind of riding you want to do. The bike you'd want to use to ride to work every day is going to be very different from the type you'd ride to race, and both will be different from a long-distance bike. Here are a few of the basic types of motorcycles and their uses.
The cruiser is based on the models made in the 1930s to the 1960s. While Harley-Davidson defined the cruiser, more or less, not all cruisers are Harleys. Many use large-displacement V-twin engines that are tuned for low-end torque. This means that they are easier to ride because you don't have to shift as much. You ride by putting your feet forward and holding your hands at about chest height, so it's a similar position to driving a car. These bikes are comfortable to ride, although long periods can lead to some fatigue.
Sports bikes, on the other hand, are built for speed, acceleration, and cornering, often at the expense of comfort. They are usually not very good on fuel economy, either. They use inline-four engines and a lightweight frame. Bikers sit forward, with their legs up closer to their body. They lean forward instead of sitting up straight, putting the rider's center of gravity above the fuel tank. At high speeds into the wind, it's easy to ride, but at lower speeds, there's a lot of strain on the wrists and arms.
Finally, there's the touring bike. These motorcycles are designed for long distance riding. They feature wind screens, large-displacement engines, and large-capacity fuel tanks. The rider sits upright, again much like they would in a car, and there is space for a passenger and for a good amount of luggage.