More NPD figures released today reveal that the entire video game industry hit a new record in 2007 with $18.85 billion at US retail alone. Only $910.7 million of that, however, was attributed to PC games - that's down 6 percent from 2006's $970 million take.

But should the PC games industry be worried by this $60 million drop? Well, not really. While the figures imply that PC gaming is a stagnant market, the PC games sales landscape is changing to one that is increasingly reliant on digital sources of revenue. The NPD Group doesn't factor in digital download revenues from services like Steam, subscriptions from MMOs like the massively popular World of Warcraft or micro-transactions. That said, consoles still vastly overshadowed the PC crowd in terms of raw game sales at $6.6 billion.

NPD also revealed the top ten best selling retail PC titles of 2007. All but four of them were part of the World of Warcraft and The Sims 2 series, with WoW's Burning Crusade expansion pack topping the list at 2.25 million copies. Other titles in the bunch include Call of Duty 4: Modern Warfare, Command & Conquer 3: Tiberium Wars, Sim City 4 Deluxe, and Age of Empires III.