This is a very old question and perhaps only the wisest sages have the definitive answer.
But it's your your taste buds that will make the ultimate decision when all is said and done.
Here are two arguments for your consideration:
"Good Housekeeping" magazine did a blind taste test and found that people could not tell the difference between hamburgers or skinless chicken breasts cooked over gas or charcoal.
But, people could tell the difference when it came to a steak.
It was decided that the longer you grill something the more the flavor of the fire gets into the food.
With that argument the hot ticket here would be the smoke.
Charcoal, produces smoke.
The kind of smoke that creates great food is the kind you get from charcoal.
Because charcoal produces smoke and heat together, the food absorbs the heat it also takes in the flavor of the smoke.
Gas grills on the other hand produces little smoke compared to charcoal.
But, not all smoke is equal.
Commercial charcoals and their cheap additives for easy lighting and their cheap charcoal made from sawdust isn't exactly the best choice for producing quality smoke.
Good charcoal mixed with chunks of good hardwood or lump charcoal made from real pieces of wood and is your secret for success.
If you are going to use crappy self-lighting charcoal then go with gas.
But if the flavor of grilled foods is important to you, and are willing to put the effort into charcoal cooking, this is the most obvious way to BBQ.
After that great argument who would want a gas grill?
First, how about the quick start to get a fire going:?
With a gas grill you don't have to calculate the right amount of charcoal, layering it correctly and the headache of getting a charcoal fire started.
Using lighter fluid to get a BBQ going quicker can leave that unpleasant odor which makes your food taste unpleasant.
Gas barbecues are connected directly to a gas line, you turn it on and you're ready to start, with no odor.
Most gas grills have a temperature control knob giving you control over the temperature, making the cooking experience much more manageable.
Then there's the easy clean up compared with the charcoal barbeque.
With charcoal, you have to wait for the charcoal to cool off and then find some way to get rid of them.
The great thing about a gas barbeque grill is that you simply wipe down the grill surface, turn off the gas and enjoy your food.
For the serious BBQ chef, who wants to spend more time with the guests than trying to get the charcoal under control, gas is the best choice.
