LOS ANGELES (Reuters) - While much of the attention at this year's Electronic Entertainment Expo is focused on new hardware such as Sony Corp.'s PlayStation 3 and Nintendo Co. Ltd's Wii, the success of the next generation of video game consoles will likely be determined by their game lineups.

E3, as the show is generally known, is the largest video game showcase in the world, and there are several titles whose presence, or lack thereof, could determine which console takes the lead in the next generation war for an industry whose revenue rivals Hollywood box office receipts.

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The console war pits Microsoft Corp.'s Xbox 360 against the upcoming PlayStation 3 from Sony (Research) and Nintendo's Wii, which is pronounced "We." The Xbox 360 and PS3 offer high-definition graphics and new speed and power, but the software is often what makes gamers purchase a system. Nintendo focuses on more child-friendly games whose characters are often more cartoonish than photorealistic.

The most anticipated title of the entire show is a game that won't be playable -- the next installment in Microsoft's blockbuster "Halo" franchise. It is widely expected that Microsoft (Research) will show a video of "Halo 3" at its press conference Tuesday, but the sci-fi game in which players shoot aliens won't likely ship to consumers until at least 2007.

"Halo" and "Halo 2," both for the original Xbox, have sold a combined 14.5 million units worldwide, according to Microsoft. The games were considered "killer apps," which drove sales of the original Xbox and helped the Xbox Live online service reach two million subscribers.

"Halo 2," which went on sale Nov. 9, 2004, sold a record $125 million during the first 24 hours.

At Sony's news conference Monday, arguably the largest audience reaction came from a video trailer for Konami Corp's "Metal Gear Solid 4: Guns of the Patriots," a stealth action title expected in 2007 for the PlayStation 3.

Microsoft also is making a huge push for "Gears of War," a highly anticipated sci-fi, horror action game from Epic Games that many think could fill the Halo gap in 2006.

"A lot of people are calling 'Gears of War' the 'Halo' for 2006," said Sam Kennedy, editor-in-chief of video game review site 1UP.com.

Kennedy says that while the big franchises like "Halo," "Metal Gear Solid" and "Zelda" are interesting, he is most excited by the largely unknown launch titles for Nintendo's Wii, which has generated buzz because of its motion sensitive controller.

"Nintendo has been saying they're going to change the way we play games, and people are waiting to see if that's the case," said Kennedy.

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