It's been 18 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 10.8%, not bad at all by historical measures. But this portfolio has lived up to its moniker as the "World's Greatest," outperforming the market by 16 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 

June 26,2011

43.1%

30%

PriceSmart 

June 28, 2011

57.3%

46%

Baidu* (BIDU -0.26%)

Sept. 15, 2012

(18.5%)

-29%

Intuitive Surgical

July 25, 2011

31.4%

23%

National Oilwell Varco 

July 28, 2011

(14.6%)

(26%)

Coca-Cola 

June 21, 2011

16.8%

5%

Whole Foods (WFM)

July 5, 2011

45.4%

37%

Amazon.com

July 12, 2011

19.5%

9%

Apple (AAPL -0.65%)

June 30, 2011

73%

63%

Johnson & Johnson 

Aug. 1, 2011

14.5%

2%

       

Total

 

26.8%

16%

Source: Fool.com, all returns as of market close Dec. 4, 2012. *Returns are for position in ATVI held from July 15, 2011, to Sept. 9, 2012, and transferred over to BIDU on Sept. 15, 2012.

Most of the portfolio is actually down since last month, with Baidu leading the way. That hasn't stopped some companies from performing well, including Amazon, which is beating the market for the first time since this portfolio began. It can likely thank -- in part -- an impressive Black Friday for its performance.

But though Amazon is doing well, it didn't make my list of four excellent buy opportunities for the month. Read below to see which companies garnered that honor.

3 best buys right now
First on the list is the aforementioned Baidu. It seems that no matter what happens, investors aren't feeling very optimistic about the future of China's largest search engine. The company has shown impressive growth over the past year, and still holds the lion's share of the search market in China.

First, competition from Qihoo 360 scared investors away; now, reports that the SEC is investigating the Chinese branches of the Big Four auditors have the market worried that we've been fed bad numbers. If that's true, there's clearly a bigger issue to be worried about. But for now, trading at just 15 times estimated earnings for 2013, Baidu looks like a pretty good deal.

Second on my list is Apple. I know that I recently wrote  about why I'm being cautious with the company, but that was more because it had grown to such a large part of my portfolio, not because it's a bad company to own. If you don't own shares of the iGiant yet, now would be a good time to start considering. As fellow Fool Evan Niu has shown, a lot of Apple bears aren't showing very good reasoning with their math. I think that, at less than 10 times expected earnings for 2013, Apple is a good buy.

Finally, we have Whole Foods. I know that many people think the stock looks pretty pricey, and with it currently at 37 times earnings, I don't blame them for thinking so. But consider this simple maxim: The highest-quality companies will always trade for a premium. Whole Foods is just over one-third of the way to reaching its 1,000-store goal, and the previous quarter showed same-store sales increasing 8.5%. That's impressive for any company, let alone a grocery store.