Which dog breed is better among Doberman,Great Dane and German Shepherd?
I want a dog which can play frisbee,etc with me and remains with me.I want it to me somewhat protective.I am 14 years old and a first time dog owner and the dog should be easy to train.

The Great Dane is a great dog, but probably not the right dog for playing frisbee and high energy sports. Although some Danes do enjoy playing and being goofy, they are very large dogs that don’t require tons of exercise and usually don’t do well with high energy sports. Great Danes are very large, and due to their size their owner must have previous knowledge of dog training to be able to assert themselves when the dog decides it doesn’t want to do something. The owner must also be big enough and strong enough to control the very large puppy, so this probably isn’t the right breed for a first time dog owner.
Dobermans are great dogs. They love to run and play so they would probably enjoy a game of frisbee. They are very high energy and need lots of exercise. Being a large dog, they can be somewhat dominant and will push their limits to see how far they can go with their owners. They are very strong willed, so this dog may be difficult for a first time dog owner to handle without practical knowledge in dog training.
German Shepherds are another great breed. They are very smart and very active. They are the kind of dog that will stay close to their owner. These dogs need a lot of socialization with other dogs and people as puppies so that they do not become weary of people and dogs as adults. This can cause them to become aggressive towards other people which is not good, even if you want a dog that will protect you. (Just a side note, any dog under the circumstances that their owner is in danger, will help their owner and protect their owner, this does not need to be trained, and training a dog for this can lead to aggression and a dog that will attack unnecessarily.) Again these dogs are strong willed and often think that their plan is better than their owner’s plan, so are often hard for first time dog owners to handle.
Of all the breeds you have suggested the German Shepherd would be the one I would say fits best, but I think there are better breed choices out there. Maybe look into a Golden Retriever or Labrador Retriever, or an English Bulldog (probably not a frisbee player though).
Good luck!
Consider the Border Collie breed
Watch this video
http://www.youtube.com/watch?v=pRFDTTU1TUc&feature=channel_page
I can’t speak for Great Danes because I don’t know a lot about them but German Shepherds and Dobermans, while brilliant dogs in the right hands, are not for first-time owners. Experience is needed to handle these dogs because they can be stubborn, overly-assertive and even aggressive if someone doesn’t know what they’re doing. You can read books, research online, even talk to other owners, but nothing prepares you for the real thing. Get an "easier" breed if this is your first time.
And if your your main reason for getting a dog is for protection, get a security system. Only licensed and professionaly-trained dogs should be used to guard or protect and they cost thousands. Trust me, you may end up with a very troublesome dog if you JUST want it to guard you.
If this will be your first dog, then NONE of these breeds are good. You need experience to handle dogs of this caliber.
They are all great breeds, (I have a dobie myself), but they are not for the first time owner. I am not trying to be mean, only honest.
I agree with the previous posts – none of the breeds you mentioned are right for a first-time dog owner. Also, since you’re 14 you might need a dog that is a little less high maintenance in the energy dept. With friends and school and homework, taking a Doberman for 2 runs a day and tons of training may not be your cup of tea for the next 8-10 years. Speaking from experience (I have a Dobie and a rat terrier), I would recommend a small terrier. The have tons of energy and can be as active as you want, but might be easier to manage. Don’t think a terrier is a purse puppy. I take my terrier for 3-5 mile runs and he only weighs 20lbs. They love fetching, frisbee, and are super intelligent. As for a watch dog, no dog is more watchful and fearless than a small terrier. It might surprise you to know that my terrier bosses the dobie around. All that and they live longer. Good luck and enjoy your dog!
Dont breed or buy then an animal in shelter dyes!
Please go to a shelter! I am 100% sure you will fall in love with at least one dog there.