It would be very difficult to find a more beneficial exercise than Deadlifts!
Besides being a fantastic lower and upper body movement, deadlifts also helps to improve grip strength, and strength of the posterior chain. It can be done for higher reps (very taxing on the musculature), or very low rep (very taxing on the CNS).
There are two main ways to do the deadlifts, conventional and sumo.
Both having distinct advantages and disadvantages, so both should be attempted to ascertain which would be best suited for your body type. In a typical gym setting, conventional deadlifts are far more common, so we will start with those.
A conventional deadlift is performed with a relatively narrow stance (around shoulder width, or somewhere slightly wider or narrower), which places the torso in a ‘bent over’ position.
Because of the trunk position, it requires more work from the lower back to extend the body as the load is lifted. Also, when pulling conventional, you must not allow the bar to drift forward and away from the body as you pull the bar upwards. This style of pulling can be problematic for people with very long femurs (the ‘thigh’ bone), as the knees can interfere with the bar’s path on the way up, or down.
The path of the bar is much longer in this lift, which can be excellent from a hypertrophy standpoint (the greater the distance you are moving a weight, the greater the amount of ‘work’ you are performing), but sometimes is not the best if your goal is to move as much weight as possible, which is why you see a lot of powerlifters opting for the sumo style of deadlift (although interestingly enough, quite often the best deadlifters do pull conventional).
The sumo style of deadlift involves a much wider stance, with the toes pointed outwards, and a much more upright trunk position. Because of this, it uses different muscles, and changes the bar path. It relies much more on the quads, inner hamstrings, and upper traps to move the weight. It requires a lot more strength and flexibility in the hips, which is why some people experience issues around the hips, and groin when they switch to sumo style. With the upright torso position, and the legs out of the way of the bar, the bar is able to travel tighter to the body as it moves upwards, and has less of a tendency to drift forward.
Because the torso is in a much more erect position, it does not involve the lower back nearly as much as the conventional style, and can be very beneficial for people with lower back issues. Also, because your stance is so much wider, your body is much closer to the ground, therefore requiring the bar to travel a smaller distance to lockout. Since the bar does not have to travel as far, less work is being completed, and oftentimes, more weight can be lifted. This is not always the case, though, as some people’s hips are not strong enough to get heavy weight moving.
Because both styles of deadlifts have distinct advantages and disadvantages, and because each relies of different muscle groups to lift the weight, I suggest trying both and, if there is no pain or biomechanical issues, performing both styles regularly and getting comfortable with each. Even if you feel stronger with one, there are many advantages to doing the other as well, and reaping the benefits of improving your weaknesses.