As I've mentioned previously, most ellipticals will have some sort of console. The most basic versions hold your water bottle, and may have some digital workout information, such as time, distance, and speed. A more sophisticated console can include calories and heart rate, an LCD screen ranging from 6-10 inches, and numerous workout programs. The more advanced the machine, the more advanced the console features (and usually the more expensive the elliptical is).
Machines with pre-programmed workouts typically have 8-28 options, often including cross-training, intervals, hills, heart rate and weight loss oriented programs. These programs are especially helpful in upping the intensity of the workout to ensure you work hard and burn serious calories. They also add that extra motivation and variety for those, like me, who aren't particularly fond of cardio. Price will vary greatly based on the console features, so it's important to consider what you and any other users feel is important for your elliptical workout.