In 1952 a British computer science professor by the name of Alexander S. Douglas created the first form of electronic entertainment, or 'graphical computer game' (because apparently calling it a 'video game' is heresy) which was called Tic-Tac-Toe. It was designed and created on this bad boy.
Interesting to note, that the systems all early computer games created in the 50's were developed on equipment originally designed for military use. Specifically missile trajectories. This included the first VIDEO GAME created by a man called William Higinbotham called 'Tennis For Two' which was created and played on an oscilloscope.
At the turn of the decade, in 1962, a young man from MIT who went by the name of Steve Russell created the first game intended for computer use called Spacewar! The game was rather simple: Two men enter, one leaves... or more or less. The set-up was two spaceships circle a planet with the intention of shooting down your opponent before you ran out of fuel.
In conclusion to all that, the first computer game was created by A.S. Dougl-- wait a minute! It wasn't because someone else thought of the idea first, and then several years later patented it therefore legally making him the creator and pioneer of the concept. This man was Ralph Baer, a Television Engineer. He created the first game to be played on a television set called Chase in 1967, fifteen years after Douglas created his game. There is some controversy about who was the real pioneer behind video games because of this. Baer held the patent because the ones before him didn't bother, seeing as the equipment needed to play their games cost over $100,000 voiding the point of a patent as none could afford it. To add further argument to this, Baer first conceived of the concept back in 1951 (a year before Douglas created Tic-Tac-Toe) when his boss asked him to make the 'best television set in the world', apparently an 'easy task' for Baer, he wanted to make a TV that could play computer games however his boss, being a dozy plonker, refused the idea.
Therefore, it's hard to say who was the first man to create a video game. It depends on what your definition of a video game is I suppose. I for one am with A.S. Douglas, ok, so it couldn't be enjoyed by the family as you'd need a massive hole burnt in your pocket and a football field sized living room to play it in but it was still entertainment created and played on a computer. Pity about Baer's idea being refused, but we can't just let history be re-written out of sympathy.
Something else worth noting is that computer games, at present, are often seen as brain-drains offering no benefit toward intellectual progression. Yet it was scientists and professors, all academics working with equipment meant for military use, that can be found at the source of it all.