According to the latest NPD Group report, total videogame software sales for October came to $513.9 million, up 39% from the same period last year. Analysts were expecting sales to come in between $550 million and $600 million for the month.

Although Halo 3 was the best selling game in October, the real star of the month is Activison's Guitar Hero III: Legends of Rock.  The game, which was released on October 28, sold 383,000 units for Xbox 360, 286,000 units for Wii and 271,000 units for PS2.

A game-only version of Guitar Hero III for PS2 sold 232,000 units.

"Guitar Hero has certainly established itself among the elite video games properties," said NPD's Anita Frazier. "Very few games sell in excess of 1 million units in their first month in market, but Guitar Hero III did easily with combined sales of 1.4 million units in only six days. Since it has broad appeal, it's also the type of game that should continue to do very well throughout the holidays."

"Guitar Hero III: Legends of Rock" earned more than $115 million in its first week on sale only in North America.

With 263,000 units sold The Legend of Zelda: Phantom Hourglass ranked fifth, closely followed by Wii Play with 240,000 units.

Electronic Arts Inc. saw its Half Life 2 title, The Orange Box, move 238,400 units for the month while its FIFA Soccer 08 title sold 129,700 units.

The last place goes to Brain Age 2: More Training in Minutes a Day! with 117,000 units.

So far this year "Halo 3" is the best selling game in the U.S. with 3.7 million units sold, followed by "Madden NFL 08" from Electronic Arts Inc