The Washington Post has published an interesting report on game reviewers and their experiences with junkets. A junket is typically an all expenses paid trip covered by the publishers in the gaming industry. The junket the Washington Post specifically covers is the Fallout 3 junket where "airfare, hotel, food, drinks and shuttle bus were provided, courtesy of Bethesda Softworks." Now, just to be clear, it's the job of publishers to do these junkets and sway opinion by whatever means necessary (and in some cases, whatever is the keyword) -- that's marketing. It's the job of the "journalist" not to be swayed by it -- that's tough and really means standing by ethics (which if the writer actually went to journalism school is the first class you take). Most newspapers have a strict policy of not letting companies pay for their writers to attend and the Washington Post points out a few attendees paid their own way, but most did not.
One writer for PC Jeux, Ghislain Masson, has been to Russia twice, India, "a five-day extravaganza in Las Vegas funded by Midway" and Paris. Of course, we stumble across moments of ethical irony often in this business and there's even moments of too close for comfort. Some would make the argument that there is a world of difference between being invited to an event and having everything paid for to attend. The question is, "Do these junkets influence the outcome of reviews?" The writers in the Washington Post piece don't believe so, but we'll leave it up to the readers to decide.
*Note: Joystiq does not and has never accepted paid junkets.