Thanks for all the lively discussion, everyone!
Just to address the main points:
It is inevitable that in a discussion such as this, that "art" must be defined. There are many different ideologies which will influence this definition. A popular post-modern definition is that "everything is art", but I feel this is interchangeable with saying "nothing is art", which is a position of despair. Regardless of your subjective opinions on which individual games/works you feel are "true art", their value is lessened by this reductive reasoning. The Urinal, for example, was brought up as example of "a terrible work of art", and then placed along side a favourite video game, which, being part of "everything" is also art. Does it not devalue what you consider the "true art", the game, to include it with something you feel is meaningless? Why not live with your convictions and argue that the game is art, and that the urinal is not?
Also, keep in mind my point about art being autonomous and judged on its own merits. If it is felt that it is unfair that modern art is pretentious and unapproachable, but considered "art" and that your favourite mass-marketed game is not considered art because it doesn't hold these pretentions, by taking each work as an autonomous entity, their circumstances and popular perceptions become irrelevant and you can judge each work as it comes and dismiss them as you please based on your ideology of art.
Next, as has been brought up by assorted people, is a matter of terminology. I believe there are differences between an artist, an artform, an artwork, and Art. Despite it being a little confusing, none of the first three guarantee existence the fourth. They are essentially a creator, the medium he works in, and the resulting product. It is the resulting product that can then be judged as art or not. You're more than welcome to disagree about the last bit, but distinguishing between the differences in terminology is important, I believe, if we are to conduct this discussion on the same wavelength.
Also, those of you to point out to argue that the battle is to have video games accepted as a medium capable of producing art. You're quite correct! Though, reading through the responses, it is also a common opinion that "everything" is art and that, therefore, "all games are art". This is the mindset I set out to challenge.
Thanks all!
Keep discussing!