I throw my hat in the sea of 9-page (at time of typing) obscurity;
I am a U.S. Citizen, I do not own a gun, and I think it is perfectly fine for civilians to own weapons.
People like to take the humanity out of problems and blame objects.
If a person wants to kill someone bad enough, they'll find a way. If you remove guns from a gun-owning society, you'll only see a significant decrease in gun-related crimes, not total crimes. Sooner or later you'll have to ban axes. Then baseball bats; crowbars, blunt object, sharp objects, hydrolics, cars, anything "dangerous".
I don't know about other countries, but when you try to ban something in the United States that people have taken for granted, you just turn regular folks into "criminals". See: Prohibition. (well, at least we got Nascar out of that... wait, is that a pro or con?). Most people won't want it for murder, they'll want it for protection or hunting or whatever, and they'll just keep their "illegal firearms".
As for "protection from goverment" and people citing how their country has no guns and they're fine, the issue is that domestic forces do not have firearms either. In countries where the government has guns and civilians don't, it generally doesn't end up well.
There has also been mention of "self-defense" or "protection of property" being invalid due to Law Enforcement. In smaller, densly populated areas, maybe. In most U.S. Cities, there simply aren't enough police officers available to respond to every call in a timely manner. In higher population areas, they also have problems with prioritizing and false alarms.
Hunting. There are very few, but still some, who hunt for food. Otherwise, it is still a sport that many U.S. citizens enjoy.
It is not easy to get a gun legally in the United States. Yes, they are sold at Wal-Mart. However, Wal-Mart conforms to the same regulations on gun sales as everyone else. There are usually only one or two salespeople who are qualified to sell them, and they have to go through separate government-administered training, like every other gun vendor. They have computers hooked directly into each State's gun registry and background check system, like every other gun vendor. People who wish to purchase a gun from Wal-Mart have to go through the same application and background check as every other gun purchaser, as well as the waiting time.
Assault-type firearms are illegal for civilian ownership in the U.S..
Those who own guns and use them for crime tend to get them through illegal means already. You wouldn't kill someone with a gun that could be traced directly back to you. If you aren't thinking clearly enough to do that, you probably want to kill them so bad you'd use whatever you could get your hands on anyway. So, criminals will still acquire guns via illegal means, citizens will be without them "for their own good", and the government will have guns as well to "contend with the criminals". How do the civilians benefit? Even in one "wiki research" presented here, the "accidental death by firearm" rate was beans.
If you want to kill yourself, there are plenty of bridges, tall buildings, freeways, poisons, pills, and good-'ol fashioned rope to get the job done without guns.
Here's the pseudo conernstone of the "anti-gun" platform: accidents. Here's what I say; personal responsibility. If you take the time to purchase a gun, you are responsible for it. You are responsible to keep it out of the wrong hands and to make sure that you only use it in a responsible fashion. As with any other dangerous item you may possess.
Again, most cultures today like to objectify problems, instead of the human aspect. People want to kill people, people want to kill themselves, people don't feel safe at home, people aren't responsible with their property. Guns are a means to express those problems. Remove them, and the problem remains.
Guns are responsible for murder and crime as much as McDonald's is responsible for me being a fatty, as Marketing is for me buying crap I don't need, as the Credit Card companies are for me being in debt. Which is, they aren't. They are all decisions people make, yes, there may be enablers, but it still comes down to personal responsibity and flawed humanity. We just don't want to admit it could be personal or societal problems, so we blame objects (that we created in the first place).