The debate over charcoal versus gas can get heated. The one simple thing you need to know is that it is a matter of taste and convenience. To gain a broader view of the whole range of grills, you need to know about electric grills, pellet grills, and hardwood cooking as well.
The best way to think about this problem is to remember that the more convenient a grill becomes the less smoke flavor it produces.
An electric grill is the easiest to use but doesn't have that real fire flavor, while hardwood fires give you the best flavor, they can be the hardest to deal with. The question to ask yourself is, do you want a fast and easy meal, or are you looking for something more. Hardcore grillers and barbecue cooks treat this style of cooking much more like a hobby that just a way to cook a meal. Of course, charcoal really isn't that complicated and with practice can be just a reliable as using a gas grill.
The authentic smoky, off the fire taste of grilled foods, is strongest with the original heat source, wood. As you move to electric units, there is very little of this flavor left. In fact, many electric grills add virtually nothing to the taste of foods. However, the simplicity of flipping a switch and grilling can't be beaten.
On the subject of taste, in a study conducted a while back participants were presented with hamburgers and steak cooked on gas and charcoal units.
No one could tell the difference between the charcoal or gas when it came to the hamburgers, but they could tell the difference with the steak. The charcoal grilled steak had a distinct smoke flavor. If you are going to be cooking larger items, particularly items that benefit from slow roasting and you want a deep smoke flavor, charcoal is the only way to go.
To decide what kind of grill is right for you, consider where the grill is going to sit. A small patio or covered area is not the place for a large charcoal grill. Electric grills produce no flare-ups and are safer in smaller areas. Gas grills do produce flare-ups and need to be away from any structure to avoid those pesky house fires. Charcoal can be lit with an electric starter and therefore, used with virtually no open flame.
Another thing to consider is how you plan to grill. If you want to come home from work and throw a couple of steaks or chicken breasts on the grill with virtually no hassle, then an electric or gas unit might be what you are looking for. These heat much faster and have the convenience of a general cooking appliance.
Finally, there is the issue of cost. Gas grills are generally more expensive than electric or charcoal; charcoal being the cheapest. If you don't want to spend a lot of money then charcoal might be the answer. However, charcoal is a more expensive fuel. You can easily spend more for a cookout on charcoal while gas might cost much less per cookout. Charcoal won't save you money in the long run, so think about the long term investment as well as the immediate purchase.