Gas smokers are easy to use and though they don't generally provide the kinds of advanced controls that Electric Smokers do, they are reliable. Gas is also a faster and more responsive fuel than electricity, though in many ways gas and electric smokers work very similarly. With a gas smoker, a small burner heats a pan of wood chips and typically a water pan for moisture to produce heat, smoke, and a moist cooking environment. The burner can produce more heat than a heating element, so gas smokers can provide better smoke. On the other hand, the combustion itself doesn't produce smoke so these units won't make the kinds of authentic smoke that a Charcoal Smoker can. Gas smokers are generally reliable though so there isn't a need to tend to them and they can be loaded up and started in minutes without having to worry about building a real fire.
Broil King 28-Inch Vertical
Broil King has been making some of the best gas grills on the market for decades. Recently they entered into the vertical smoker market with models like this one. The price is higher than the competition, but this is a well built gas smoker than has a good sized capacity and is simple to use. Probably the biggest standout feature of this smoker is that among the competition, it is the only one produced in North America.
Smoke Hollow 38-Inch Two Door
Like most of the gas smokers on this list, the Smoke Hollow 38-Inch has two doors so that the wood and water pans can be accessed without opening the food chamber and releasing all the heat and smoke. This model also has a glass door so you can see the food without getting inside. As the saying goes, if you are looking you are not cooking. With this smoker, you can look and cook. The construction of this model is better than most, but like the others on the list, this is a metal box with a gas burner. It isn't complicated, but then again, that's the point.
Masterbuilt ThermoTemp 340G
Masterbuilt has been in the little box smoker business for a very long time. Their electric unit is one of the best selling on the market. This new gas powered model has an improved look, glass door and two access points so you can keep the food cooking while replenishing wood and water as necessary. In general, this is a typical gas smoker, but considering the overall quality, it is one certainly worth looking at.
Weston 36-inch Outdoor Vertical
This Weston Gas Smoker has a stainless steel door, and while it only has one door, it has power and good construction quality. This smoker isn't widely distributed, so finding it can be a bit of a challenge, but I do recommend taking a look. It is one of the best build gas smokers on the market today.
Dyna-Glo 43-Inch Wide Body
This monster from Dyna-Glo has more capacity than any other on this list. In fact, it has nearly twice as much as the next biggest gas smoker. If you need the capacity, it is hard to find a unit larger than this one. Considering the price (typically around $250USD) is is the least expensive per square foot of cooking capacity, so if you need to produce a lot of barbecue, this might just be the perfect unit for you.
Pit Boss Vertical
Pit Boss started life making temperature control equipment for smokers. Now they produce a whole like of grills and smokers. This new gas smoker from them has an access drawer and glass door and a great design. Couple that with an efficient design, good capacity, and solid construction and this looks to be a serious competitor in the gas smoker market.
Cuisinart Vertical 36-Inch
Cuisinart has been expanding slowly into the outdoor cooking industry for years. This new gas smoker with their name stamped on the front has a classic design but no viewing window. It does have a second door for access. It is also the least expensive gas smoker on this list, so that is certainly a consideration.
Smokey Mountain 38-Inch Two Drawer
The Smokey Mountain 38-Inch has independent drawers to access either the wood or water pans. They are relatively small, for a smoker of this size, but this is still a good smoker worth considering. This unit is wide so the food sits up front for easy access. Smokey Mountain has made outdoor cooking equipment for many years so there isn't a risk in buying this unit.
Camp Chef Smoke Vault 24
Camp Chef is known for their affordable outdoor cooking equipment. This is a very simple and inexpensive gas smoker, but it lacks access to the wood and water pans and the door is a little lightweight. While not a bad purchase, I would seriously consider the smokers above before buying this unit.
Everyone knows the Char-Broil brand and this gas smoker from them is certainly competent. While inexpensive, the capacity is low and due to its somewhat narrow design, it can have trouble fitting many of the foods you might want to smoke. At around $200USD though, it is affordable and not a serious investment for someone who wants a small smoker for simple foods.