Many gifts fall flat. After tearing off the wrapping paper, the recipient, while cringing inside, struggles to feign delight. In fact, an estimated $46.3 billion of holiday goodies will be returned this year, up 10% from two years ago, according to the National Retail Federation.

Even recipients of bigger ticket items wrestle with the eternal post-holiday question: Keep it or return it? In our first installment we looked at the year's most popular gadgets. Now SmartMoney.com asked the experts which of 2011's hottest toys are worth keeping.

Leap Pad Explorer

Keep it:
One of the hottest sellers this year at $99, the tablet computer for kids is already out of stock on many shopping sites. Chris Byrne, content director of TimeToPlayMag.com, advises parents and children who got one for Christmas to count themselves lucky. "LeapFrog has been a leader for many years in this market," says Rick Singer, CEO of GreatApps.com. "I don't think parents or people giving it as gifts have the eBay mentality of just selling it for a profit or taking advantage of a hot item."

Return it:
If it's not a big hit with the kids -- who may prefer to play with their parents' iPads -- return it for altruistic reasons so children who really want it can have one, Singer says. On a more mercenary note, Byrne says it might be worth selling it online instead of returning it given the demand. Currently, they are selling for up to $165 on Amazon.com, and went as high as $200 before Christmas. However, Byrne says, "Once it's opened it loses some of its resale value."

Air Swimmers Flying Clown Fish

Keep it:
These inflatable sea creatures appeal to both adults and children, according to Bob Friedland, a spokesman for Toys R US; Toys R Us used them to draw customers into their Black Friday sales. Plus, he says they tend to make people laugh. "Keep the fish because it's super cool and will wow everyone who sees it," Byrne says.

Return it:
That said, it's a helium balloon cleverly fashioned into a shark, Byrne says. "It's a great item, but may not be for all households or families." Given the nature of the inflatable beast, it may scare smaller children, annoy adults and get in the way of more pressing activities like cooking in smaller houses, he says. And, at $40 a pop, it doesn't come cheap. In those cases, more than one of these items is best brought back -- while it's still in the packaging.

Polaroid 300

Keep it:
Aside from the obvious nostalgia value, this camera can produce an actual print within a few minutes, and has four lighting settings and an auto-flash that make life easy for amateur photographers. Plus, it costs around $90 -- not bad for a camera, according to Singer. "The camera really is a classic in the same way that it seems records or LPs are," he says. In the future, this too could become a collector's item.

Return it:
However, experts say that film will need to be purchased separately and it works out at around $1.30 per print. Others feel the Polaroid 300 is too gimmicky and there are other cameras that will educate children in photography. Plus, they say the novelty of instant photos wears off pretty quickly. "Invest the money in a better point-and-shoot that your child can grow with like an entry-level Kodak EasyShare," says Louis Ramirez, senior feature writer at dealnews.com.

Let's Rock Elmo

Keep it:
This doll is more interactive than previous versions of the cute little red monster. As SmartMoney.com previously reported, Jerry Perez, senior vice-president at Hasbro, says the new Elmo is updated for the modern kid, but retains the "beloved" character's likability and innocence. It costs $69.99 and comes with a drum, tambourine and microphone, or a total of $100 with all the accessories. "The interchangeability of the instruments provides a little more play and interaction than many so-called "watch me" toys," Byrne says. "If your kid is a real Elmo fan and gets a kick out of repeat play with this toy, it's charming and certainly quintessential Elmo in its humor and exuberance."

Return it:
If the family budget is tight, think twice, experts say. Byrne says all the accessories can really add up. Let's Rock Elmo has a a range of them like the Cookie Monster Keyboard, costing from $18 to $25. And since Amazon.com is currently selling the toy with a 36% discount, Byrnes says it's possible to return it for the full price and save money by purchasing it again. The collectible value may be diminished, as toymaker Hasbro's latest offering didn't cause the same craze that Fisher-Price's "Tickle Me Elmo" did in 1996 -- when it sold out in stores across the country, experts say. "If a child is not likely to engage with this product over time, you might be better off with some of the basic Sesame Street toys," Byrne says.