Though Tesla (NASDAQ:TSLA) has repeatedly struggled to meet production targets for its its "affordable" Model 3 electric vehicle, investors can't deny that the company has massively over-delivered in another area: share price gains. Tesla stock has soared more than 720% over the past five years as of this writing, leaving long-term investors considerably richer for their patience.

Are there any other stocks worth buying today that could outshine Tesla in the coming years? We asked three top Motley Fool investors to chime in. Read on to learn why they like Under Armour (NYSE:UA)(NYSE:UAA), AIG Warrants (NYSE:AIG-), and A.O. Smith (NYSE:AOS).

Woman in business suit drawing a line with her finger indicating exponential gains

IMAGE SOURCE: GETTY IMAGES.

This rebound is just getting started

Steve Symington (Under Armour): Formerly a market darling in the eyes of growth investors, Under Armour has plummeted nearly 70% from its all-time highs. For that, it can blame a combination of an increasingly crowded retail market and a crippling slowdown in its core North American wholesale business, as multiple sporting goods retailers have declared bankruptcy in recent years.

At the same time, the worst appears to be over for the athletic apparel and footwear specialist. And the market has begun to reward investors: Under Armour stock has rebounded almost 40% from its 52-week low, including a massive single-day pop last month, after the company's burgeoning international and direct-to-consumer businesses (where sales grew 47% and 11% year over year, respectively) helped the company return consolidated revenue growth in its fiscal fourth quarter of 2017. 

And while expectations are still low for Under Armour in North America, one of its key competitors may have just offered a light at the end of the tunnel. On Thursday, Nike (NYSE:NKE) stock climbed after the company confirmed that while its own sales declined 6% in North America for its fiscal third quarter of 2018 (ended Feb. 28), it believes that North American revenue should flatten out next quarter before returning to year-over-year growth in the second half of the calendar year.

Of course, I can't guarantee that the rising North American tide will lift all boats. But given Under Armour's recent signs of stabilization and its still severely depressed stock price, I think long-term investors would do well to open or add to a position before even more tangible progress in its turnaround becomes evident.

A bold bet on one of the largest insurers

Jordan Wathen (AIG warrants): There are few bargains in the financial industry, but AIG warrants offer an interesting speculative bet that could produce high returns for investors in less than three years.

AIG's post-financial-crisis experiment in tapping insurance outsiders to run the business proved to be unsuccessful. Ex-CEO Peter Hancock took AIG on a course to cut fat and eliminate non-core businesses, but underwriting performance was poor under his leadership. Hancock was the man AIG needed years ago, when it was suffering from bloated operations, the result of its desire to grow at all costs before the financial crisis. But AIG's biggest problem was tied to its underwriting and its inability to price risks.

In my view, AIG took a big step forward in 2017, when it hired longtime insurance executive Brian Duperreault, who began his career as an actuary at AIG in the 1970s. Duperreault steps into a leaner company that needs underwriting expertise, which he brings in spades.

I think the best way to bet on AIG is to buy its warrants, which give investors the right to buy shares at roughly $42.70 before expiration in January 2021. Warrants work like stock options, and investors have nearly three full years to benefit from a turnaround before the warrants have to be exercised.

Assuming book value grows to $80 per share before expiration from retained earnings, and shares trade back to book value, warrants purchased at a recent price of $17 would more than double in value in less than three years. I think combination of improved insurance pricing (thanks to the hurricanes and wildfires of 2017) and an actuary at the top of AIG can help it finally earn a double-digit return on equity and trade back to book.

It's far from a guarantee, but if you want high returns, you have to be very comfortable taking higher risks.

Big growth potential from a boring business

Reuben Gregg Brewer (A.O. Smith Corp.): Electric cars appear to have a huge future -- but so do water heaters, which is A.O. Smith's specialty. You probably take your water heater for granted, unless it stops working. But residents in emerging markets like China and India, where hot water isn't a given, are eagerly buying water heaters as soon as they can afford them.

Just how eagerly? Over the past decade, A.O. Smith's revenue growth in China has exceeded 20% annually. And it's only just starting to get serious in India. Sure, the business is expected to grow in the mid-single digits in developed markets (around 65% of revenue), but higher growth in emerging markets (35% of revenue and mostly consisting of China and India) is expected to push overall revenue up by around 8% a year for the foreseeable future. It's also entering the water and air purification markets in these nations, since clean air and water aren't things you take for granted in emerging markets, either.   

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So far, investors have rewarded the company well for its success, pushing the stock up more than 700% over the past decade. To be fair, that's a much smaller gain than Tesla's stock achieved over the same span. But over the past three years, A.O. Smith has actually outperformed Tesla. Boring can, indeed, be nice. On top of that, add in a steadily growing dividend -- the company is up to 25 annual dividend increases -- and 1% yield.

If you're a growth investor looking for a little dividend income, forget about money-losing Tesla and take some time getting to know A.O. Smith's boring, and steadily growing, water heater business. 

The bottom line

Tesla has set the bar high, and there's no way to absolutely guarantee that these three investments will go on to beat the electric-vehicle maker -- whether that means rivaling its past returns or outperforming it for the foreseeable future. But given Under Armour's ongoing turnaround, the speculative promise of AIG warrants, and A.O. Smith's steady business and favorable long-term trends, we like their chances of doing just that. 

Jordan Wathen has no position in any of the stocks mentioned. Reuben Gregg Brewer has no position in any of the stocks mentioned. Steve Symington owns shares of Under Armour (C Shares). The Motley Fool owns shares of and recommends Nike, Tesla, Under Armour (A Shares), and Under Armour (C Shares). The Motley Fool has a disclosure policy.