One item on the holiday gift-buying list is definitively shaping up to be most coveted — and most difficult to find: If you missed out on buying a Nintendo Wii during the holiday season last year and have it on this year's list, you had better start shopping now.

Retailers can't keep the still-popular game system (price starts at $250) in stock a year after its debut. And the Wii is the top-requested game system on holiday wish lists, according to a new Weekly Reader Research survey of 1,000 8- to 17-year-olds for retailer Game Crazy. The Wii was on 32 percent of wish lists, the Sony PlayStation 3 on 19 percent and Microsoft Xbox 360 on 17 percent.

"Our recommendation: If you see one now, buy it," says Brian Lucas of Best Buy.

Customers in Hawai'i are asking for Wii, but the supply also remains tight here in the Islands.

"We didn't get ours," said Windward KB Toys manager Shannon Vertido just before Black Friday, the busiest shopping day of the year.

The imbalance of demand and supply for the Wii confounds retailers as well as consumers. "We don't always know when and what we will get," says Circuit City's Jim Baab. "When we get inventory from Nintendo, we put it out and it generally sells within a couple of hours."

Nintendo, which has sold more than 5 million Wiis, recently increased the number of units expected to be shipped worldwide by the end of March to 17.5 million from 16.5 million. "Consumers are going to have to stay on top of it, but we have definitely ramped up," spokesman Perrin Kaplan says.

The demand for the Wii recalls that of the PlayStation 2, which after being launched in 2000 also remained elusive more than a year later, says NPD Group analyst Anita Frazier. "The Wii is going to be in short supply this holiday relative to the strong demand," she says.

This year has marked a reversal of fortune for Nintendo. Its previous GameCube system came in third in worldwide sales to Sony's PlayStation 2 and Microsoft's Xbox. For most of this year, Wii has outsold Xbox 360 and PlayStation 3. Only in September, thanks to the release of "Halo 3," did the Xbox 360 outsell the Wii (527,800 to 501,000, according to The NPD Group).

Nintendo's momentum also extends into handhelds, selling about 4.5 million DS systems ($130 to $150 each) this year, more than any of the console systems. "These systems are highly entertaining but relatively intuitive," Kaplan says. "That is what really fits into global lifestyles."

Nintendo's competitors, particularly Microsoft, are now courting the same family and casual gamers attracted to the Wii. A new $280 Xbox 360 Arcade version comes with games such as "Pac-Man" and "Uno." Also just out for Xbox 360: "Viva Pinata: Party Animals" ($50), the trivia game "Scene It?" ($60) and a free new feature to limit a youngster's time on the system.

"Microsoft is livid that Nintendo has taken the lead in the console wars with a technically inferior but more-fun-to-play system," says Geoff Keighley, host of Spike TV's "Game Head." "Microsoft has struggled to make the system appeal to a broader consumer. Games like 'Rock Band' and 'Guitar Hero III' will help, but both of those titles are also available on the PS3."

Sony also hopes to woo shoppers weary of searching for Wiis. Recently, Sony chairman Howard Stringer said PS3 sales had more than doubled since Oct. 18, when Sony reduced the price of the 80 GB PS3 model to $500 from $600. This month, it also began selling a 40 GB model for $400. "It's a little fortuitous that the Wii is running out of hardware," he said.

Determined Wii shoppers may want to look online — and be ready to loosen their wallets. Amazon is not selling any Wiis directly, but on a recent Monday, about 90 third-party sellers were offering new and used Wiis starting at $460; eBay has similar prices.

Bundles were listed in stock on Walmart.com starting at $677 (with seven games), with delivery by Nov. 29. The Wii is out of stock at GameStop and Electronic Boutique Web sites, but each is taking pre-orders for new systems with five games (starting at $585) expected to ship Dec. 17.

But supply is not guaranteed. "Our stores will have them from time to time, but we are encouraging people to shop early because this year there are going to be a ton of kids of all ages with the Wii on their wish lists," says Chris Olivera of GameStop. "Consumers are just going to have to be very diligent."