Odds are, you'll be using your winch off-road. You have two options here: a winch mounted on the front or rear bumper of your vehicle. Depending on the weight of your vehicle and the weight of the winch, it can be used to pull your vehicle out of the mud or pull other vehicles free of sand, muck and mountain streams.
The most important thing to consider is how you'll be using your winch, especially in relation to the weight and frame strength of your vehicle. Spending the money on a heavy-duty winch is a waste if your vehicle can't support the winch's power. Instead, shop around for one with an appropriate amount of power, also known as 'line pull.' Line pull is the maximum load the winch can exert on the cable. While you can't go wrong with extra energy, not enough power will leave you stuck. Even worse, if the winch is too heavy, it could cause the front end of your vehicle to shift off balance.
When considering the speed at which you want to haul things in, there are two options: a planetary gear train and worm gear train. For the fastest line speeds, get a winch with a planetary gear train. Some are faster than others, but nearly all perform well under varying conditions. For a steady pace with less heat, look into a winch with a worm gear train. Worm gears have fewer moving parts and can work extremely hard without creating a lot of excess heat. Something else to keep in mind is whether you prefer to use cable, wire or chain. These would also vary depending on the application and your level of experience in hauling.
Finally, you'll need to decide between an electric or hydraulic winch. Each type has its own benefits.
Electric winch is easy to install and, in most cases, simply bolt onto your rig with a couple of wires running up to your car battery. Most winches, like the Warn winch, Blazer winch, Mile Marker winch and Chevy winch, are available for both the older 24-volt systems and the more modern 12-volt setups. Electric winches are the most convenient when you want to take them off during the off-season. Hydraulic winches also feature continuous pull time and, as such, are able to be used non-stop for extended periods of time. Plus, your rig doesn't have to be running to use a hydraulic winch, saving you from burning the valuable gas you're going to need to get back down the mountain.