I am a 37 year old man and I still like video games.
I am not ashamed of this, as aren't we all really just kids at heart? A video game is just a game played on your TV, so the notion that they are only for kids is ridiculous. If this the theory that video games are only for children held true then all games would be for children (be that a board game, video game, game show or whatever). I, for one, don't think games are just for kids, they are to be enjoyed by people of all ages, video games included.
The video game industry recognizes the popularity of video games amongst the 'older' population and many of the games they produce should not be played by children at all. They contain mature themes and visuals, heavy on guns, horrific violence and blood. The rating system on video games is very similar to that of the motion picture industry, and parents should make sure they are educated on what their children are playing (maybe by sampling the game themselves before purchasing or allowing their child to play it). I would wager, however, that close to half of all new games are actually marketed towards adults. Games like Grand Theft Auto and the Tom Clancy Series are huge franchises and giant money makers for their respective companies.
My generation was really the first to be introduced to video games, and as a whole I think we never really grew out of it. What is really exciting is how far they have come in terms of graphics and game-play. Kids really have no point of reference so they do not realize how far the games have come since the days of 'pong' and the first Atari game systems. Additionally, the video games played on the Internet are very popular with adults and can be a great diversion from work (just make sure the boss isn't looking).
Another subject that should be addressed here is the fact that video games are glamorized by rap singers and athletes. Adults see their sports and music idols playing the games and it makes it that much more acceptable to them. Video games also seem to be a huge part of the marijuana culture (which many adults obviously partake in).
Personally, I am addicted to Tiger Woods Golf on my Playstation3. Not only is this game amazing to play, but I swear it's helped my real golf game. It is strikingly authentic and the graphics are crisp and quite realistic. I would usually rather play the real game, but when the weather does not permit, kicking back on the couch for a good game of Tiger Woods is pretty entertaining.