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 5,400 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 four-star firms approaching greatness.

  • Hewlett-Packard (NYSE: HPQ)
  • Internap Network Services (Nasdaq: INAP)
  • Isis Pharmaceuticals (Nasdaq: ISIS)
  • Western Digital (NYSE: WDC)

Some of these names might surprise you. For example, computing giant Hewlett-Packard is buying almost $4 billion worth of companies this month (3Par and ArcSight) and it's making a major investment in its Palm purchase. Almost great? Even familiar names can still offer some of the best opportunities. Perhaps we've just forgotten the potential they still hold.

Last week we pointed out how Western Digital and rival Seagate Technology (NYSE: STX) were sporting miniscule margins as the market mispriced the value traditional storage systems still hold. However, the 170,000-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?
Another storage name exhibiting weakness is LSI, whose revenues in its most recent quarter missed analyst expectations and came in at the low end of its own guidance. Inventory adjustments at customers who were previously buying up product in the first quarter hit its results, and LSI issued a cautious outlook for the third quarter.

The apparent misstep doesn't much concern CAPS members who still strongly support the chip maker. CAPS member jsGreenmachine says it's been through the cycle before and will be around to go through it again in the future:

Chip maker that has out-lasted most firms through the cycles. Top decision makers know what it takes and the time is now!

On the shoulders of giants
Datacenter operator and Internet traffic router Internap Network Services continues looking to new markets for growth, including content delivery network services. But revenues fell 6% last quarter as the switch from reseller to facilities-based datacenter provider tries to gain traction. The controlled churn has eaten into the top-line numbers, but margin expansion is under way, suggesting the bundling of services that it's undertaking is paying off.

Before you rush to buy in, note that it's bumping up against industry leader Akamai Technologies (Nasdaq: AKAM), which handles about 20% of all Internet traffic, Limelight Networks, and Level 3 Communications. There's no shortage of competition in this space and Internap will need to distinguish itself further.

The CAPS community remains solidly behind Internap, however, as 92% of those rating it think we'll be seeing market-beating performance in the months ahead. You can add your ideas on whether the change will work out as planned on the Internap Network Services CAPS page and put it on your My Watchlist page to find all the Foolish news and analysis about the company.

A big opportunity
It was a scene we've seen played out before at Isis Pharmaceuticals, which reported that cholesterol drug mipomersen had similar outcomes to phase 3 data reported earlier this year. With severe liver enzyme-elevating side effects, Isis and Genzyme may find their treatment has a narrower patient population to attract, but the ability to significantly reduce cholesterol levels will enable them to still generate sales, just at a much lower level. That's good enough for CAPS member irishred1, though, as Isis is still financially sound:

robust balance sheet, a good entry into RNAi along with ALNY, and believe that mipomersen has a good shot at approval even if its use will be restricted

Although Isis went on to report an earnings loss that was wider than anticipated because research and development spending rose, management hopes full-year losses will be smaller because of a new partnership with GlaxoSmithKline.

A great opportunity for you
Investor sentiment suggests these four-star investments still seem to be on their way to five-star greatness, but 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.

Akamai Technologies is a Motley Fool Rule Breakers selection. GlaxoSmithKline is a Motley Fool Global Gains recommendation. The Fool owns shares of GlaxoSmithKline. Try any of our Foolish newsletter services free for 30 days.

True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community. The Motley Fool has a disclosure policy.

Fool contributor Rich Duprey currently does not own any stocks as you can see here. The Motley Fool has a disclosure policy.