As a long time Wikipedia editor, and a short time Giant Bomb Wiki editor, I can see a few pages of the Wikipedia playbook that would be excellent additions to Giant Bomb's Wiki.
Problem: A large number of pages need to be re-written for style, grammar, and POV. Many game articles read more like reviews and use the second person.
Solution: A template mechanism to tag pages in need of certain types of editing. On wikipedia, for example, if I use the Template:Cleanup-tense, then it will list that article on http://en.wikipedia.org/wiki/Category:Wikipedia_articles_with_incorrect_tenses. This way, if I notice an article written in second person, I can simply tag it. Later, if any editor wants to tackle fixing articles with incorrect tenses, they can simply navigate to the category page, and fix them one by one. This sort of tagging for cleanup issues is extremely efficient.
Problem: Releases are presented in an unfriendly, long list.
Solution: Releases should be presented in a single grid, so that a reader can quickly compare, say, the publishers of the same game in different countries; or features of a game on one platform compared to another. Moreover, a user should be able to enter in release information for multiple countries and platforms at once, because most of the data will be the same across platforms and countries. The fields should auto-populate with the most recent data, and then the editor only needs to change country or platform specific info. Platforms should be on the grid in chronological order of release, and alphabetically for simultaneous releases (e.g. the virtual console release should be the last one on the list, because it is furthest removed from the original release).
Problem: The right side of articles are very messy
Solution: The "features" and "multiplayer" infoboxes should be completely hidden (not ghosted) for games that have no features listed. This will clean up the right side of the article for just about every classic-era videogame. Even when games have a limited number of the features, it should be a short list of features the game supports, not a huge ghosted box of (arbitrary) features it does not. This also goes for the supported resolutions, ratings, widescreen support, etc... for classic era games. They will always be N/A and convey zero information while cluttering the right side.
Problem: Distinction between "platform" in the game features box, and "releases" is confusing, despite various forum threads.
Solution: Every game should require "releases" to form the article. The "platform" data should auto-populate based on releases. If you want to add Xbox as a platform, start the Xbox release, and it will populate the platform. This has the side benefit of many articles lacking releases, even though consoles are listed. Further, the platforms and releases should both be in an intelligent order, which is chronological by release, and alphabetically for simultaneous releases. It's insane that the first Platform on the Super Mario Bros. page is Gameboy Advance.
Problem: It's not obvious how new articles are started
Solution: A simple form for new articles would be useful.
The design philosophy behind wikis is dynamism. Keep improving it, tweaking it, building consensus. It's very frustrating editing wikipedia video game articles, because there are strict notability requirements, and source requirements. There is a ton of freedom at Giant Bomb that I love - I can write an article about an obscure game for the Atari without having to find sources. The inherent notability of published games makes it a ton of fun to write here; the mechanisms for doing so could stand improvement. It would be excellent to compile and pin a requested features list, and build consensus as to which features and implementation thereof are worthwhile.