Last year was great for many investors, with a bevy of companies posting consistently stellar results, with the share price appreciation to show for it. But some stocks, including Qualcomm (NASDAQ:QCOM), Nokia (NYSE:NOK), and Zulily (NASDAQ: ZU) were either overlooked or left by the wayside altogether. All offer compelling stories and, according to several of our contributors, are underdogs worth considering for 2015.

Bob Ciura (QCOM): Qualcomm is an underdog that could be a top stock in 2015. Investors were apathetic toward Qualcomm last year, but this was based on headwinds that I believe will be short-term in nature. Qualcomm shares are down 1% over the past year, compared to a 9% gain for the S&P 500 Index. Investors seem preoccupied with Qualcomm's regulatory troubles in China, where the company believes licensees are under-reporting device sales numbers. And, Qualcomm's business practices are under investigation in China and the U.S.

But while it's easy to overreact to these problems, investors are missing out on the long-term picture. Qualcomm's business model remains strong and it continues to see robust demand for its chipsets. In fiscal year 2014, Qualcomm earned $26.4 billion in revenue and nearly $8 billion in profits. Earnings per share jumped 19% from fiscal year 2013. Total MSM chip shipments totaled 861 million units, up 20% year over year.

Its stellar cash flow allows Qualcomm to reward its shareholders with aggressive cash returns. Qualcomm returned $7.1 billion to investors last year through share buybacks and dividends. The company repurchased 60 million shares last year, and with its stock price stuck in the mud, each dollar spent on share buybacks will create even greater shareholder value.

The global smartphone boom shows no signs of ending any time soon. Technology industry research firm IDC estimates global smartphone shipments will grow 12% in 2015. Qualcomm is a major beneficiary of this. Investors who aren't afraid of the current headline risk surrounding the company are treated to a cheap stock at just 12 times forward EPS estimates and a 2.4% dividend yield as a very nice kicker.

Tim Brugger (Nokia): What a difference a year makes. At this time in 2014, Nokia was still a mobile phone manufacturer, along with its networking and maps businesses. But with a new year comes a new Nokia, and investor's would be wise to take notice.

The new Nokia is a streamlined, revenue-producing machine consisting of three business units. In the recently completed Q3, $3.4 billion of Nokia's $3.9 billion in total revenues came from its high-performing Network unit. Like each of Nokia's business units, Networks improved compared to Q3 2013, up 13%. Nokia's highly regarded mapping solutions, also enjoyed double-digit growth in revenues compared to 2012.

Nokia's valuable patent portfolio continues to pay handsomely as demonstrated by the 9% improvement from the Technologies unit, the group responsible for maintaining, and growing, Nokia's patent properties. With so much sales growth, earnings up 50% year over year, a 2% dividend yield, and future guidance above earlier estimates, Nokia's share price must be flying high, right?

Luckily for investors, the answer is no. The first trading day of 2014, Nokia was priced at $7.94 a share, slightly above today's share price. Why? Nokia hasn't shed its underdog reputation despite its solid performance, and therein lies the opportunity for investors in 2015. In addition to expectations for continued growth along with its decent dividend, Nokia is trading at a very respectable 19 times future earnings. That's not quite bargain-basement pricing, but it does represent good value.

Rich Duprey (Zulily): Considering 2014 started off on such a high note for mom-focused e-commerce retailer Zulily it must be especially galling how it ended: It's lost 44% of its value this year and is down nearly 70% from its 52-week high. So, things can only get better in 2015, right?

Not quite. As I've recently noted, Zulily faces a couple of problems that will hold it back. For example, it routinely has email issues that wreak havoc with its ability to get messages out, which ends up impeding its customer list-building efforts. Analysts expect fourth quarter new customer activations to slow appreciably.

Zulily also suffers from slow delivery times. While customers aren't looking for overnight or two-day shipping options like on, delivery often lags compared to rivals like Rue La La and Gilt. Such a glacial pace inhibits its appeal to new customers.

So why can Zulily still be a top stock in 2015? Because management recognizes its shortcomings. Although they've dismissed the email snafus by saying they work through them with their provider when they arise, repeated "email deliverability challenges," as they call them are unacceptable. Management will be forced to address them, which will work to its benefit.

Similarly, Zulily's delivery time issues didn't include inventoried items. When those are considered, the e-tailer's numbers markedly improved. They still lagged, but Zulily sharply closed the gap. With a new warehouse being built, and possibly more to come, those sorts of differences may be negated.

Zulily is still perfecting the inventory-lite model and will likely continue experiencing periods of volatility. But moms seem to like its flash-sales, which should push revenues higher. Having fallen so far after growing so fast, we may just see Zulily's stock be a star performer this year.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.