We have a great dane (great pain) LOL
Her name is Emma, and she s 2 years old. She s a little over 3' at the shoulder, about 120 pounds...
Very active, loves to run and terrorize anything that moves, hates bicycles, baby strollers and lawn mowers.... ABSOLUTELY loves car rides, especially in the land cruiser (its the only vehicle we own that she can stand up in!)
She does not like children-- however, this is not characteristic of the breed. Typically danes are great with kids, however emma is a rescue dane from an abusive household, and we believe it was a child who hit her and abused her as a puppy.
Aggression is a difficult issue, and u get lots of answers... a good rule of thumb-- fawns are the most mellow, halequins are the most aggressive. Oddly, males seem to be better with children than the females....
as far as security goes, nobody comes within about 100 yards of our house. A dog like this, the size speaks volumes, even though she is sweet as molasses and u would literally have to be killing one of us for her to bite u. People literally see u coming and clear the path.... Like having the SUV of dogs.... they make great city dogs, despite their size.. they can run in a small urban yard like ours.... they do get on furniture, as they sit on anything that s at their butt level which pretty much means anything that s at ur butt level. they will rest their butt on the sofa and have front legs on the floor all day long. (While watching TV nonetheless) Emma loves accordian music. Eating off the table or counter is an issue, as the top of most tables are below eye level....
Downsides: have a good food budget-- plan it like u had another person in the house to feed... i d say plan to spend about $2-3 a day once they are adults.... They need lots of toys, and we have yet to find anything this dog cannot destroy within hours. The giant rawhide bones last about 15 minutes....
One thing about danes that many people will tell u is that they do not live long. This is true in many cases when compared to other dog breeds. It is not uncommon for a dog to live only 8 -10 years. However, the more exercise u give the dog, and proper high qulaity diet, and they are known to live up to 14 or 15 years.... For emma, we give her small amounts of dry and canned food, but the bulk of her food is a mixture of cheap ground beef (like the 30% fat stuff that comes in the big plastic tubes at the supermarket) supplemented with other meats, as well as fresh garlic, *ground* veggies like red cabbage, and some olive oil. Organ meat once a week will keep ur dane in top condition. This may sound expensive, but for a dog of this size, we find home made natural food to be only *slightly* more expensive (pennies a day) compared to a higher quality canned/dry mix. Lot of exercise is great too. Even though our emma is an urban dog, we do run and walk her lots and she loves hiking and camping.... and twice a month we load her up in the cruiser and take her to our friends farm when she runs miles and miles and miles and ......
They are very intelligent-- sometimes too intelligent for their own good. I dont reccommend a dane for person who is not strong willed and willing to show their dominance over the dog every day. Their size deceives them and makes them think they are ur equal, or worse, ur superior. U need to make ur dominance known from the start or u will get walked on-figuratively and literally! These dogs have narcissistic tendencies and are legends in their own minds... If u ask emma, she would tell u she owns the house, all of the cars, everything in them, and would insist she is on the title deeds for them all, and she is nice enough to let us sleep here and borrow her cars. It s only by keeping strict rules that we let her know she s not in charge.
Danes are not for everyone, but if u have one, and if they are right for u, u will never want another dog. And yeah, it is great to walk down the street and have people clear the sidewalk and give u a large berth.... and when we had a spate of break ins in our neighborhood, our house was avoided all together. Emma makes her presence known to anyone, she s hard to miss, and lets face it, they can look downright mean when they want, but for the most part they are 120 lb lap dogs. LOL
Clearly, the human breed of landcruiser owners has much more to offer this world than the average bear. 
I'll be talking to the owner tonight. 
