As 2011 comes to a close, it's a great time to look back at what happened to the stocks that interest you. By making sure you know the important things that a company accomplished -- as well as the setbacks it experienced -- you can make a better decision about whether it's a smart investment for your portfolio.

Today, let's take a look at ExxonMobil (NYSE: XOM). The largest stock in the U.S. market rode high oil prices to another banner year, with truly massive revenue of more than $100 billion every quarter. But with a huge array of smaller companies to bet on, is Big Oil still worth your investment dollars? Below, I'll take a closer look at the events that moved shares of ExxonMobil this year.

Stats on ExxonMobil

2011 YTD Return 19.3%
Market Cap $408 billion
1-Year Revenue Growth 28.4%
1-Year Earnings Growth 50.1%
Dividend Yield 2.2%
CAPS Rating (out of 5) ****

Sources: S&P Capital IQ; Motley Fool CAPS.

Why did ExxonMobil do well this year?
As energy goes, so goes Exxon. That's a simple rule that's even more apt after the company bought XTO Energy last year to become the largest natural gas producer in the country, beating out Chesapeake Energy (NYSE: CHK) and other companies known more for their gas exposure. Like fellow giant Chevron (NYSE: CVX), Exxon has been pushing for broad-based energy dominance.

But to do so, Exxon operates in some risky parts of the world. In Russia, it agreed to a joint venture with Russian state oil company Rosneft, despite concerns that arose after Royal Dutch Shell (NYSE: RDS-A) ended up having to give up control of its Sakhalin project to Russian gas giant Gazprom five years ago. Exxon also plans to make huge capital investments in Iraq, where competitors like Eni (NYSE: E) and BP (NYSE: BP) are trying to take advantage of war-ravaged oil fields that need renovation. In Venezuela, after suffering alongside Total (NYSE: TOT) when Hugo Chavez nationalized the oil industry, Exxon is still negotiating to try to get at least some compensation for the assets that the dictator took.

Exxon may not have the growth potential that tiny exploration companies offer. But it also comes with a lot more stability and security. Conservative investors have to be pleased about another healthy year for Big Oil's biggest player.

Still, if you want a more exciting stock in your portfolio, we've got another energy company you should look at closely. Read about it right here in the Motley Fool's special free report on the energy industry and its best prospects. But don't wait until it's gone -- get it today.

Click here to add ExxonMobil to My Watchlist, which can find all of our Foolish analysis on it and all your other stocks.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.