Some companies are obviously great investments -- in hindsight. Yet for every stock out there screaming "buy me," others simply give us a nudge and a nod. How can we tell tomorrow's obviously great investments from the thousands of pretenders?

The stars' walk of fame
On Motley Fool CAPS, these opportunities can be found among our four-star stocks. In CAPS' proprietary ratings system, they rank higher than most of the other 5,300 starred companies, but they're just shy of superstardom. While all the attention might be focused on their five-star peers, we can sift through CAPS to find four-star firms approaching greatness. Here are a handful of examples:

  • AK Steel (NYSE:AKS)
  • Cypress Bioscience (NASDAQ:CYPB)
  • IMAX (NASDAQ:IMAX)
  • SanDisk (NASDAQ:SNDK)
  • Texas Instruments (NYSE:TXN)

Some of these names might surprise you. Texas Instruments, for example, has been a semiconductor industry leader for decades -- and despite the industry downturn, it still ranks high in investor sentiment. Almost great? Even familiar names can still offer some of the best opportunities. Perhaps we've just forgotten the potential they still hold. However, the 130,000-plus CAPS members chose these companies as less obvious sources for tomorrow's great buys, so let's see why they might merit your attention.

In the sight of greatness
There are few immersive movie-going experiences that can top watching a film shot with IMAX technology. And some of the most anticipated movies of the near future will be released in the format, giving rise to hopes that IMAX will report blockbuster numbers as big as the films its screens project.

The latest graphic novel-turned-movie, Watchmen, may be the one to surpass industry game-changer 300, which helped popularize the genre. The latter film opened on 71 IMAX screens and generated some $20 million in IMAX revenues; Watchmen opened on 124 screens with revenues anticipated to be as much as $35 million. The movie grabbed the top spot this weekend, and IMAX reports its theaters were sold out. Going reel-to-reel with a string of future big hits coming to the big, big screen later on this year -- including Marvel Entertainment's (NYSE:MVL) Transformers 2, a new Harry Potter installation, and the animated Monsters vs. Aliens from DreamWorks Animation (NYSE:DWA) -- IMAX could be given the red-carpet treatment come earnings time.

Meanwhile, making more IMAX screens available has become more affordable. A theater can be converted to an IMAX production through the wizardry of digital projectors for a third of the cost of building a dedicated theater, not to mention the reduction in costs for distribution. Also, while a dedicated IMAX print can cost tens of thousands of dollars, the new digital projectors can play versions that cost just a couple hundred bucks.

That should help soften the blow of the premium theaters charge for an IMAX screening. It's hard enough shelling out $10 a stub to see a movie without adding in an extra fee for IMAX. While theaters might enjoy the bonus, investors aren't as upbeat about the prospect for IMAX theater proliferation. CAPS member systemchalk sees an IMAX showing as a luxury item that won't do well in a recession:

Large format is a luxury for only the biggest budgets and then only for specific scenes. It is more expensive to shoot, limiting in the noise it creates and in the time it takes to load the magazine. High definition cameras, are cutting costs and becoming much more 'set friendly.' As a display format expense again becomes an issue. Studios stand to save billions in prints if theaters were to go to digital projectors, and yet comparatively few have crossed over. If theatre owners haven't paid for digital, why would they pay to convert to IMAX (traditional or digital)? IMAX cannot take off unless the cost of installing it is less than conversion to a standard digital projector, or the means of acquisition (cameras, film stock) become more production friendly.

A great opportunity for you
These four-star investments could be on their way to five-star greatness, and it pays to start your own research on these stocks on Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from a stock's CAPS page.

Sign up today for the completely free service and let us hear what you have to say about the great -- and almost great -- companies that interest you.

IMAX is a Motley Fool Rule Breakers selection. DreamWorks Animation and Marvel Entertainment are Motley Fool Stock Advisor picks. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Rich Duprey owns shares of DreamWorks but does not have a financial position in any of the other stocks mentioned in this article. You can see his holdings here. The Motley Fool has a disclosure policy.