It's been almost 21 months since I introduced the World's Greatest Retirement Portfolio to Foolish readers. This was, has been, and will continue to be my way of helping the world to invest better. Putting my money where my mouth is, I pledged to put at least $4,000 behind each stock and attempt to hold each one for at least three years -- though I've already broken that promise.

Since I began, the market has returned 18.2%, which is fantastic by historical measures. But this portfolio has lived up to its moniker as the "World's Greatest," outperforming the market by about 12 percentage points.

Below, I'll show you why it's doing so well, offer up three stocks that I think are excellent buys right now, and offer access to a premium report that offers deeper analysis than I can cover in one article.

Company

Publication Date

Change

Vs. S&P 500

Google

6/26/11

56.5%

36

PriceSmart 

6/28/11

55.1%

36

Baidu* (BIDU 0.62%)

9/15/12

(2.2%)

(20)

Intuitive Surgical 

7/25/11

43.2%

28

National Oilwell Varco (NOV -0.42%)

7/28/11

(7.8%)

(27)

Coca-Cola 

6/21/11

17.1%

(2)

Whole Foods (WFM)

7/5/11

55.7%

40

Amazon.com

7/12/11

25.6%

8

Apple (AAPL -0.35%)

6/30/11

36.8%

20

Johnson & Johnson 

8/1/11

21.1%

1
       

Total

 

30.1%

11.9%

Source: Fool.com. All numbers accurate as of market close Jan. 31, 2013. **Returns are for position in ATVI held from July 15, 2011, to Sept. 9, 2012, and transferred over to BIDU on Sept. 15, 2012.

It's good to see that the portfolio is up slightly from last month, despite the plunge that Apple took after its earnings release. Though I think that shares of the company are pretty cheap right now, I've voiced some long-term concerns about its ability to innovate in the post-Jobs era and will be holding off from including it on this list for now.

3 best buys now
The first company that did make the list for this month is National Oilwell Varco. Though the company took a dip after earnings were released, I think long-term investors have a lot to like from the report.

On the whole, the company has three segments: rig technology (which accounts for roughly half of the company's revenue) was up 30% on the year; petroleum services (about 33% of all revenue) was up 23%; and distribution revenues (which account for 20% of the company's revenue pie) was up an impressive 110% on the year.

The reason the company is trending lower is that there are worries about weakness in onshore drilling in North America. While there's no denying this, it comes with the territory when a company has its hand in all things energy like National Oilwell does. The good thing is, when one segment declines, others usually increase. COO Clay Williams says that segment will likely be deepwater rigs. I think the recent pullback offers a good entry point for investors.

Next on the list is Chinese search giant Baidu. The company reported full-year results that were nothing short of impressive: growth in revenues and EPS of 54% and 57%, respectively. The company took a beating yesterday, however, because of concerns about higher expenses and the ability of the company to monetize on mobile. But if we've learned anything from Google, it's that mobile searches can be monetized, and spending now to earn more later is worth it. 

Finally, I think Whole Foods' shares -- while not being particularly cheap -- are worth buying now. I won't waste space here telling you why, as I just wrote about why I'm buying shares of the company for my Roth IRA here.