My labs have been eating Eukanuba for about 3 years now all together. It's definitely my personal favorite - it was my vet's recommendation, and it has surpassed my expectations. Best dog food, in my opinion. I originally got it because it is gentle on my dogs' sensitive stomachs, but it's good for any dog, really. It has an excellent blend of proteins and vitamins, and my dogs certainly seem to like it It's available most places that sell dog food.
Every dog is different and some will do better than others on different foods however Euknauba is not really a good quality food. There are some in their range better than others but most are not very good quality. Vets will always recommend any food they sell. Mine sell hills and Royal canin but I wouldn't use any of them when there is so much better out there.
I have picked one out which shows it is not very good, http://www.allaboutdogfood.co.uk/dog-food-reviews/0095/eukanuba-adult-large-breed
They also own pedigree, frolic which again are very poor quality foods
What owners feed to their dogs is down to personal choice and we all have our favourites but the all about dog food site is a great resource to use.