The reason that most games do revolve around killing in some form or another is that game developers are unimaginative and that killing is fun and they know that it works. New concepts that doesn't involve killing is risky. Major game developers do not want to take too huge risks financially and this I can understand. This is one of the reasons why independent studios are important for the game business.

Another reason that GameRager TM mentioned is that games are escapism and therefore less bound by our morals, thus it is very easy to include some form of violence in a game unless you specifically try to avoid it. This does not explain why violence is such an important part of many of the games made.

It must of course be mentioned that man is a violent creature. We have a predisposition for it and women less so (I'm generalizing). This is probably an important reason for why men are more interested in computer games than women (I'm generalizing even more). Even so, I don't think that predominantly violent video games is something we would necessarily have ended up with if history had taken a different course somewhere. We are predisposed for many other things than violence, for example sex and social interactions. I think both of these could have been more important parts of computer game evolution if history had taken a different road. I think that it is our culture that have decided that violent video games are (mostly) acceptable.

Violent video games do however seem a lot more healthy than social videogames. Social videogames and other types of virtual social interaction have a rather unfortunate effect on many people where they seem to trade their real social interactions for virtual social interactions.
Just think what will happen when someone makes a successful social sex environment on the internet through some kind of input\output that connects with the sex organs. Kinnect is not it but we are getting there. And since I would prefer our numbers to dwindle rather than to grow I say: Go for it fuckers.

But back to what I originally wanted to say. I would like more less violent games. It is not that I don't enjoy kicking around Zombie heads in Blood or standing next to someone in Fallout and open him up a little with my minigun. Nor is it that I think violent video games makes healthy people more violent.

It is just that I'd like a little more variety. Take CRPG's. If I say a less-violent CRPG many would probably think about a really dull game or something similar to Planescape Torment. Planescape Torment is not the solution for most studios because it requires a considerable talent for story-telling. (Besides, story-telling should not be the main priority for most computer games. It is a lot more important in the CRPG genre, but it is not not required. An alternative to mostly linear story-telling is open-endedness, choices-and-consequences and letting the player fill out with his\her own imagination.)

I think a less violent CRPG could still be as fun and involving as the violent ones we have. But you would have to trade in the violent parts for something else. A very important part of CRPG's is the combat. And the combat is interwoven with another very important part, the statistics. Could somebody come up with something as exiting as combat and with as many tactical possibilities? I think so.
If there was much less violence in this theoretical game and it was a game with a setting or story that made you take the game seriously, the violence when it arose, either through the players optional actions or because of an NPC's actions would be much more horrifying and gruesome than in a normal game. Just like it is in a serious movie where you believe in the characters as real persons rather than the puppets and livestock of many action movies.

This would be great also in a quasi-medieval fantasy setting where a man's life is of very little worth and horrible things lurk in the dark of the forest since neither a common man nor a knight in shining armor can fight like a superman. A more realistic approach to violence would be good for many reasons.

I'm not saying that I do not like the type of games we have today (and the games of "old") and their unrealism, I do! And I hope more classic CRPG's, strategy games and action games will be made (they will!), but I hope for more realistic and less violent games in the future and I think they will be made since the average age of gameplayers will become higher and higher.

Violence can be a good from of spice in both fairy-tales, movies, computer games and folk music, just remember that there are advantages to not overdoing things too.

Toki Tori! It's awesome and non-violent!

Uh...it probably says something about me that my two most-played casual games are "Toki Tori", where you guide a cute little chicken to safety, and "Foreign Legion: Buckets of Blood", where you gun down terrorists by the gazillion.

If Peter Molyneux made "Toki Tori: Buckets of Blood" and the standalone expansion "Toki Tori: Even more Blood" would you play it?

...
...
...yes? -.-

I would love it so...

Lemmings and Frogger are great and good games but they are very violent! Perhaps Toki Tori is not.
True. I guess the essence of what I'm trying to say is that type of video games we are seeing today is just a very tiny fraction of the possible types of video games that could be made with our current technology and still be as fun as those we have now.

The most violent thing you can do in Toki Tori is freeze an enemy in a block of ice temporarily. It's all about avoiding them and rescuing chicks.

Shell yeah!

Maybe a pinball simulator? I've been thinking of picking one up from GOG, so that's what naturally came to mind whn considering non-violent games.

Myst series?

But you beat the poor balls so very hard....

...so Casino Royale had pinball torture?

This is true. Chessmaster, perhaps?

Chess not violent?

Well, it's really only violent in the most abstract sense. Unless you're playing Battlechess. Then it's a bit more graphic. Regardless, it is a combative game, so I suppse that alone might disqualify it from the OP's consideration.

I enjoy violence in all it's glory and non-violent games, it depends what mood I'm in. I'm looking forward to Bulletstorm but at the same time if they came up with another (good) simcity I'd be hooked on that just as much.
I don't see what's wrong with violence in games, even in a purely sensationalist tone; at the end of the day those games are designed for adults and if you don't want to play them you don't have to; there's plenty of other genres out there that have heaps of non-violent games on offer; E.G: racing, point & click, city building, puzzle, relaxing, sports, rhythm, Barbie, platformers, financial, political, boardgame conversions, etc.

Violent games (fps mainly) just tend to provide a quick gratification which make them better as pick up & play games & they tap into survival a little bit with the whole kill or be killed, gotta be quick, attitude.