Warren Buffett has blessed the world with many great one-liners and quotes -- millions of his fans know a few of them by heart, but I think this one is my favorite:

"Marrying for money probably isn't a very good idea under any circumstances, but if you're already rich it's crazy."

Till death do us part
We all know somebody that makes brilliant decisions in every aspect of his or her life except for relationships. Often, these folks are consistent winners in the business and investment world. Unfortunately, losing at just one or two relationships can cost a lifetime's worth of smart decision making.

For decades now, Warren Buffett's stock recommendations have performed even better than his relationship advice.

Secrets to Success
The secrets to Warren Buffett's success are straightforward. Rushing into marriage (or a stock) is risky, so Warren Buffett reduces this risk by only dealing with people he likes. He takes his vows seriously, once settling down with a stock he expects to hold it for a lifetime. Knowing even the strongest relationships have ups and downs, communication is critical. Losing faith (selling out) during down times is easy -- these moments require patience. Warren Buffett stayed in Omaha, Nebraska for fear of being over-stimulated in the big city. Jumping around from stock to stock (person to person) can be dangerous; it will not lead to Buffett-like success over the long term.

3 Stocks Berkshire Hathaway can wed for life
Recently, Buffett renewed his vows with ExxonMobil. Looking in the portfolio, it's obvious Berkshire Hathaway (BRK.B -0.69%) likes big energy names, financials, and insurance. But it could use some diversification into forestry and strategic metals. Pages of text would be required to highlight the intrinsic values of each business, so I'd encourage you to further your research into each.

1) Freeport-McMoran (FCX 2.23%) is led by an honest and capable management team. Freeport's global footprint stretches from the Americas to Indonesia. A portion of its proven reserve base holds 116 billion pounds of copper and 32 million ounces of gold. In a cyclical industry, Freeport has demonstrated its ability to survive the ups and downs. Needed for electricity, copper is intertwined with our daily lives. Every automobile has at least 50 pounds of copper in it -- out of sight, but almost always there. Copper's even helping with Internet traffic. It will be just as important 10 years from now as it is today.

2) Plum Creek Timber (PCL.DL) is a low-tech business. Buffett's philosophy recommends staying within one's circle of competence: Stick with what you know. Do you think land and lumber will still have value 10 years from now? If you do, Plum Creek Timber would be a great long-term stock for any portfolio. Plum Creek Timber controls one of the largest, most geographically diverse land and lumber banks in the world. More than just slum lords of the forest, Plum Creek's team of foresters are great custodians of it. I'll go out on a limb to call them conscious capitalists. They strive to make every acre of land the best that it can be for all stakeholders: community, environment, employees, and shareholders.

3) More than 56% from the peak, Goldcorp (GG) is one example of being greedy when others are fearful (at least relatively fearful) -- so easy to say and so hard to do. At just 1/20 the price, Goldcorp is like the ExxonMobil of gold. If Joe Sixpack and Joe Banker still want gold 10 years from now, Goldcorp is willing and able to mine it for them. It has 67 million ounces of reserves still in the ground. Goldcorp is king of Ontario's Red Lake district, one of the most prolific gold zones in the world. "If you're right about what, you don't have to worry about when very much"- Buffett.

Modesty is the best policy
True Buffett fans already know that deep down Warren likes gold (and even diamonds!). Ben Bridge, Borsheims, and Helzberg are all subsidiaries of Berkshire Hathaway. Rather than flaunt his family jewels all over town, Warren prefers to own the whole store. That's it! The crowning jewel in Warren Buffett's investment philosophy. Whether you own 1 share or 1 million shares of stock, you're part owner in the business. That's the mentality he was taught to have.