Facebook's (Nasdaq: FB) IPO has turned into an unmitigated disaster. But investors shouldn't allow that stock's failure to entirely sour their view of the recent crop of IPOs to flood the market. Sure, many of these are Facebook-ish with their scant financials, dim hopes for the future, and occasional near-absence of traditional shareholder powers. There are, however, several potential diamonds among those low-value stones. Here are three to keep an eye on.

Surprisingly good for you
In those long-ago days before Facebook face-planted (e.g., this past April), it was common for new issues to pop high on their first day of trading. But very often they'd experience gravity soon after, tumbling down to the level of their issue price or even lower.

This has not been the case with Annie's (NYSE: BNNY), which in late March hit the market like a rocket on caffeine -- the stock's issue price was $19, and it closed at nearly double that by the end of its first day of trading. That price is still holding nicely, thank you very much, at just higher than $41.

It helps that the underlying business at Annie's is solid and produces results and growth. It also has an excellent business profile as a maker of pre-packaged foods that, in contrast to tradition, are actually made with natural ingredients and thus healthier to eat than the usual offerings from the competition. Not going the typical chemicals-and-preservatives route of the more established prepared food concerns strikes a chord with consumers. These days, they have as little time as they've ever had to prepare meals, but they're also much more health-conscious. Annie's does a fine job squeezing into this convenient-but-nutritious niche.

And Annie's is profiting from it. The company's sales grew a robust 22% annually in its most recently reported fiscal year (to March 2011), and its net margin came in at a weighty 17%. The latter fell to the single digits in the March-December 2011 period, but sales continued to grow at nearly the same pace.

This company is also restless and innovative -- two investor-pleasing traits. Its 2009 foray into snack foods has brought in the bucks, with the company more than doubling its sales in the category over the ensuing two years, from $21.8 million to just under $45 million.

Molding a profit
One downside of being a high-octane IPO is what occurs when the stock runs low on gas. That's what happened to Proto Labs (NYSE: PRLB) this month, when the formerly soaring company announced its quarterly earnings. These were fine, even topping analyst expectations, but the firm offered guidance for the upcoming quarter that was below what the market would have liked.

That's not usually a coffin nail for a typical stock, but Proto isn't the typical stock. Like Annie's and other certain social networking companies we could name, Proto's share price had blasted ahead on its first trading day, ending at $29 -- or 81% higher than the issue price of $16 -- and then soared as high as $39. It's likely that investor hopes were so unrealistically high by that point that a price crash was inevitable sooner or later.

Since that scary fall (which saw the shares collapse by 22% to a little under $29.50), the stock has recovered to the mid-30s. Although this price looks a bit rich on the surface -- at around 39 times forward earnings versus analyst expectations of 32% EPS growth over the next two years -- the company's full of potential and its stock still has upside, in my opinion.

This is because Proto occupies a compelling niche with high barriers to entry. It makes molded plastic parts on demand and delivers them rapidly (sometimes within hours) to its clients. That's a neat and very useful business line, and the technology behind it forms a wide competitive moat separating Proto from potential rivals.

Lastly, the company seems to be on the right track in terms of operations. Its revenue is growing fast (by 34% annually to a record $30 million in its most recent quarter), and it's been consistently profitable so far.

A flight to quality
The airline business is famously brutal, what with its constant threat of labor unrest, tight regulations, and high input costs. It's hard even for established operators to stay solvent, let alone turn a profit under such pressure. Bucking that trend is a small company punching above its weight class, Spirit Airlines (Nasdaq: SAVE).

Unusually for an airline, Spirit has not only posted a profit in its most recent quarters and fiscal years -- it's managed to keep its margins fairly steady over those periods. And these margins are wide; in its most recent quarter, the figure stood at just less than 8%. Contrast this with another discounter, the much larger Southwest (NYSE: LUV). That airline's most recent quarterly net margins barely squeezed through the departure gate at 2.5% and 3.7%.

Spirit turns the profit it does in part by being leaner than the competition. It operates from a somewhat off-radar hub, Fort Lauderdale, and limits its routes more or less exclusively to popular destinations in the U.S., the Caribbean, and Latin America. Unlike Southwest, it offsets its low ticket prices by charging for nearly every service a passenger might possibly require during the flight -- not only for checked luggage but also carry-on bags, seat requests, and on-site printing of boarding tickets.

Investors aren't crazy about airline stocks, but they like Spirit. The stock currently trades at $20.78, for a fat premium of 73% over the company's issue price of $12. At the moment, the stock's forward P/E is 8.6, which is quite low for a firm that's expected to grow EPS by 73% over the next two years.

Social media -- good tool, bad investment
In the wake of Facebook's stock price crumble, we can expect potential underwriters to be fairly gun-shy about bringing new companies to market in the near future. However, there are at least a few recently listed companies out there with better potential for investors -- both in terms of stock price upside and fundamentals. We should use Facebook only as a way to post holiday pictures and connect with our friends; other freshly minted stocks are more deserving of our investment money.

There are, of course, plenty of good stocks to buy that have been on the market for a while. We've picked a crop of market veterans that are attractive enough even for the most skeptical old pros in the investment game. Find out which stocks they are in our free report "The Stocks Only the Smartest Investors Are Buying," which can be downloaded right here.