Big Green Egg if you choose charcoal... the reasons are many and I've owned various charcoal grills for over 10 years
It has a lifetime warrenty on the ceramic and 5 years on all other parts... you can grill (sear steaks at 700F) or slow cook ribs at 250F... it also does great brick oven style pizzas... well worth the money if you want to buy a quality grill. The temperature control is amazing for a charcoal grill and I can hold the temp within a few degrees for hours. You can basically get the precision of an range oven with the flavor of a charcoal grill and it doesn't dry out food like a gas grill would.
You need to buy through a local distributor though and not online because it will void your warranty... if you live in a big enough city you can usually shop around and get a better price. I would recommend the Large for most people because it is big enough for a family and the XL uses too much charcoal. If you are only cooking for yourself or one other person a Medium or Small is adequate but spring for a Large if you can because you'll never need to buy another grill again.