A good variety is what's best. Lamb is all around an excellent choice, but variety can be key to your dogs health if you're deciding on making your own dog food. Dogs vary on whether they like fish or not, and even if your dog likes it, it should be served sparingly due to levels of mercury and other heavy metals found in most fish (1x every 2 weeks is good). Chicken is also excellent, just be extra careful not to serve with any bones as chicken bones splinter and can lead to serious injuries. No turkey ever! Some dog foods contain small amounts of turkey, but if making your own please just avoid it. Turkey can have serious and even deadly affects on dogs/cats. If you're trying to decide what flavor of dog food to purchase (because frequent changes in food can mess with a dogs tummy) then is go lamb. Please read the ingredients carefully and choose a food that list your meat of choice FIRST. This means that the meat is the largest portion of the food. Rice is also a key ingredient to look for. Some foods use corn as a filler, and corn boasts very little nutrition. You want rice as your filler. It's healthier, less likely to trigger allergies, and less likely to promote obesity. I worked for a vet hospital for many years and had a close relationship with food reps.
The Lab needs a balanced diet just as you do.. Good dog food contains meat, grains, and other nutritional additives. You can save money by buying bulk food at a place like PetSmart and bring your own container. This is still much healthier for the dog than an all meat diet.