I've read a lot of speculation about comparisons of BBY and GME on this board so I thought I'd give my two cents on the subject.
As most of you already know, a high P/E is not a bad thing if you have strong growth.
1) BBYs huge box stores and staff have a lot more overhead and other expenses vs. GME stores, which are usually just a hole-in-the-wall in a high traffic area (i.e. malls) staffed by two or three people at a time, often part-timers, which are cheaper than full-timers.
2) BBY sells a vastly diversified stable of electronic goods and accessories. In a bad or uncertain economy, sales of big ticket items such as large TVs and home theater systems, or higher-end laptops and computers (some costing as much as a decent used car) will probably be the first to take a hit. These items comprise a substantial percentage of floorspace in the average Best Buy and are constantly burning up electricity. Also, competitors will be cutting prices in a bad economy to compete for a percentage of a smaller pie. Whereas GME is in the sweetspot with a limited range of products, but in very high demand and more consoles sold means, more demand for games for those consoles. GME's online store supplements the need for more retail space to stock games.
3) Game Stop has developed a strong brand awareness with young people and bought out it's closest direct competitor EB Games. And most of the driving force of hot title sales comes from free word-of-mouth pre-hype from kids and gamers anticipating the newest "must-have" release. Therefore, it does not need to spend millions of dollars per quarter on advertising, ala BEST BUY, Circuit City.
4) GME is developing more of an international presence (currently approx. 25% of stores) which can help with currency fluctuations. BBY also has expansion plans but it takes lees time and financial commitment to open up a small Game Stop store than a Best Buy. Look at what happened to WalMart's over expansion over the past several years.