I have lived with many individuals in both breeds.
While each dog is unique, these are my observations:
Labradors:
1) Cleaner, since they have short coats
2) Require less brushing
3) Have healthier skin and are slightly less prone to hot spots and skin infections
4) Shed more- and since their hair doesn't come out in clumps, it's just hairs all over everything you own. Plus, their sharper hairs thread into your furniture, clothes, and the interior of your vehicle
5) Are loud- they bark more, are more protective, more vocal in play, and tend to scream, howl, and cry in their crates when bored or excited (like if they heard someone come to the door, mine would scream and bark this awful high pitched cry if they were crated and wanted to come say hello). This, in fact, is one of the main reasons I will probably never foster or own another Labrador. basically, they are intense, and tough- which makes them such great duck dogs!
6) They love to swim and retrieve, and they are great walking buddies
7) It's not difficult at all to off leash train them, once they have a strong bond with you
8) They bond more tightly to one person than does a Golden, and they are also more protective. This "one man dog" trait is the primary thing about them that I think they have over a Golden Retriever
9) Female Labs, especially, are often quite intelligent
10) They are bolder than a Golden- they also, as a result, have a kind of bull in a China shop personality, and will not let anything stand in the way of their fun.
11) They're the superior breed for field trials- they are not as sensitive, and they can take harsher training than a Golden can
Goldens:
1) Prettier, IMO, because of the coat
2) Less hair in the house, with routine brushing, since most dead hair will come out in clumps in the brush
3) More sensitive, less pig headed, and therefore somewhat easier to control, though there are exceptions (usually teen-aged males)
4) Less protective- worthless watch dogs
5) They don't bark. I can count on one hand the times I've heard a Golden Retriever bark, even at the doorbell, and I've had over fifty of them
6) Easy to crate train- one mild "Stop that!" is usually all I have to do to teach a Golden not to cry in the crate, even as a baby puppy
7) They are less "one person" than a Lab, and have a tendency to be flakey and run up to everyone they see and treat that person as their long lost best friend- I hate this, personally, but I know others like it. This is the one thing I don't like about Goldens.
8) They are messy- they drip when they drink, like a Lab, but they also track in more dirt.
9) Their coats need to be kept clean, or else they get infections. They also cannot be left wet. Invest in a power dog blow dryer, and dry your dog every time he swims or is bathed, unless you're going to walk him/towel him dry. Putting a Golden up wet to lie in a crate on his damp body will cause hot spots.
10) Goldens cannot usually take harsh training, though there are some tougher skinned ones out there
Both Breeds:
1) Have extensive health issues- ALWAYS buy from a reputable show or performance breeder who does all clearances
2) Do NOT get a field bred dog unless you are very active
3) Do NOT let the dog become overweight. The chunky look is more than ugly- it's deadly. This is vital with these breeds. Almost all Goldens and Labs I see out and about are fat. Don't add to this. A correct specimen is rarely over 75 pounds for a large male, unless the dog is over sized, which he won't be if you followed the advice in number 1) and got one from a good breeder
4) Feed a top food, and avoid corn, wheat, and other allergins.
5) Clean the ears regularly, and again, feed good food- both breeds tend towards ear issues