There are a few things to consider when buying a new barbecue grill. First will be the size, which will be determined by the number of people you usually cook for. The other things to consider are grate type, burners, finish, side burner, and the cart.
Cooking grates are made out of many different materials. There are three types of grates:
Basic: Made of porcelain enamel-coated steel wire and not designed to leave good searing marks. Porcelain Enameled Cast Iron: Designed to give you great searing marks and retain heat well. Cast iron grates have a tendency to rust, but with a porcelain enameled finish you don't have to worry about rusting for many years. Stainless Steel Rod: These grates will never rust and leave professional searing marks. They have great heat transfer into foods being cooked.
Another thing to consider is the burners, which provide the heat for the cooking surface. The burners can be made out of different material. The lower-end models come with a stamped steel and only last 1-2 years. Stainless steel is what you want. These burners run the full length of the cooking box, have a longer life span, and create an even heat throughout your cooking surface.
The finish on the grill is also important. Most barbecues today come in either a porcelain enamel or stainless steel finish. Both cook equally as well, but with a porcelain enamel finish you're not going to see any water marks; making it easier to maintain a clean look. Stainless steel, however, always shows fingerprints, but regardless of the maintenance many people still love the look.
Next thing to consider is the cart. A fully-enclosed cart will protect the barbecue’s flame from being blown out on windy days, keep the grease cup from little critters, and is great for storage.
When buying a barbecue grill you should also consider a side burner. Some side burners are designed just to keep food warm, but if you’re looking do more with your grill, like steam lobsters, you will need a side burner with at least 10,000 BTU
Also note that if you’re buying a new gas grill, it’s recommended that you replace your LP tank. LP tanks are only good for five years and are stamped with the date of manufacturer in the upper right hand side. This is regulated by the D.O.T. and it is illegal to fill any tank that is more than five years from date of manufacture.