It is interesting to see the different responses. Space is a consideration. It wouldn't be right to have 3 big dogs in an apartment. The temperament of the dog would have to be considered. As Victor mentioned, some breeds don't do well with other dogs--even of the same breed. The cost should be figured in, too. The more dogs you have the bigger the food and veterinary bills. If you can only afford one dog, you shouldn't have two.
I always thought I wanted two dogs. I've been satisfied with one. It fits my lifestyle and my pocketbook. She is attached to me, but she loves her "Grandma", too. Well, she pretty much loves everyone in the family.
Themdno, no offense taken. I have read that two dogs can be buddies since they form a pack. My dog, though she is the only one in the household, has contact with other dogs. Everyone in my family has a dog. I've taken care of my sister's dog many times. I think it is important for a dog to be socialized with other dogs. A puppy needs to be around adult dogs as they learn some of their manners from them.
Sandooch, the memories of puppydom! That may be why I only have one dog at a time. You need a break so you can forget that horrible first year where they aren't potty trained and chew everything up. Oh, and teething! Misha gnawed the edging off her plastic crate during the worst of it. I'm not sure I could do two puppies at the same time. That is for sure!