A well-crafted watchlist is critical to smart investing: It can help you find attractive buying opportunities, and it can save you from bad decisions.

After all, investors can be their own worst enemies. When we overreact to the day's news, we make rushed decisions driven by emotion. A watchlist can help you slow down the process, examine the risks, and essentially take a deep, money-protecting breath. The Fool now offers MyWatchlist.com, your customized hub to follow the performance and Fool news and commentary about the companies you're watching.

But what to put on your watchlist? Today, Inside Value advisor Joe Magyer shares a pair of companies that have taken up residence on his watchlist, and one that he recently bought for himself.

One to watch
These days, Joe recommends buying outstanding businesses with wide moats at good prices. Granted, as the advisor for Inside Value, he's pretty much saying that all the time, to the point where it could be considered a mantra. Still, Joe says that the task is easier in today's market environment.

Retail giant Wal-Mart (NYSE: WMT) tops his list. With more in sales per year than most countries' GDPs, the business offers decent upside from today's prices. Its 2.2% dividend is on par with a 10-year Treasury note, and its competitive advantage makes it about as safe from risk. In fact, there's very little not to like about a purchase here. But because Joe's been talking it up so frequently to the members of his service, he hasn't found a window in which he's allowed to buy, based on the Fool's trading guidelines. Instead, he waits and watches.

Two to watch
On the other end of the spectrum, Joe is also bullish on Google (Nasdaq: GOOG), a company that confounds the typical value investor.

"With Wal-Mart, you can tangibly understand the competitive advantage and the value of the company," says Joe. "But a lot of value-oriented analysts think two guys in a garage could take out Google, that it's nothing more than a search engine and a few algorithms. They ignore the fact that Microsoft has more cash on its hands than it knows what to do with, and still it hasn't been able to unseat Google on search."

Moreover, the company is far more than a way to find pictures of seahorses or the directorial resume of Ben Affleck (two actual Google searches I've conducted in the past two days; don't ask). Joe says that investors are dramatically underestimating the value of the irons Google has in the fire, ignoring that the company has been able, for example, to monetize even an erstwhile boondoggle like Google Maps. The folks in Mountain View have become quite adapt at leveraging their search advantage into other lucrative avenues.

And one he bought
And now for something completely different. As a Buffett-worshipping, moat-seeking value hound, Joe rarely finds himself sniffing around microcaps. In China. In the midst of accusations of fraud.

"Just a bit outside my wheelhouse," he concedes.

But Foolish colleague Tim Hanson, the advisor of Global Gains, knows and loves China Green Agriculture (NYSE: CGA), a tiny Chinese company that makes fertilizer. Its shares got hammered after fraud accusations, and Joe's inner value-alert started buzzing.

"It's a riskier investment than I would normally make, but I looked at the given range of outcomes and thought it was a good pickup," says Joe. "I'd been watching the company and suddenly the shares were just too cheap not to buy for a little portion of my portfolio."

That's exactly why it pays to watch. You can make smarter investing decisions with your own version of My Watchlist, new and free from the Fool. Click below to start following one of the stocks mentioned above:

Roger Friedman doesn't own shares of any companies mentioned, but they're all now on his watchlist. Google and Wal-Mart are Motley Fool Inside Value picks. Google is a Motley Fool Rule Breakers selection. China Green Agriculture and Wal-Mart are Motley Fool Global Gains recommendations. The Fool owns shares of China Green Agriculture, Google, and Wal-Mart. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.