Like most investors, you probably aim for the best possible return when picking potential investments. But as consumers increasingly clamor for companies to embrace social responsibility, good corporate citizenship is becoming a vital part of many companies' success. And it can boost the performance of our portfolios, too.

CR magazine recently released its "100 Best Corporate Citizens" list for 2013, in which it rated members of the Russell 1000 large-cap index on 325 different elements related to responsible behavior. In the coming weeks, I'll delve into each of the seven categories that contribute to a company's overall score.

Today, we'll look at the philanthropy category, which gets a 9% weighting. Here are the top-rated companies:

(MSFT 0.23%)

Albemarle (ALB -5.30%)

Weyerhaeuser (WY -2.20%)

FedEx (FDX -0.68%)

Intel (INTC -0.14%)

To earn their high scores, the companies above engaged in a variety of good practices such as paying employees for some of their volunteering time, loaning talent, and permitting the use of facilities. Each company's total annual giving was also considered.

Digging deeper
So what, exactly, are these companies doing right? Here are a few examples of their philanthropic practices:

Microsoft founder Bill Gates is well known for his massive giving, but the company is no slouch, either. In the past 30 years, Microsoft employees have contributed $1 billion to tens of thousands of nonprofits. Add together the company's donations of cash, software, and services, and the total exceeds $6.5 billion. Some 65% of employees participate in the company's giving program, and since 2005, they've volunteered more than 2 million hours. Microsoft matches eligible employee donations to charities each year up to $12,000.

Albemarle, a Louisiana-based specialty chemical company, has established a foundation that has contributed more than $14 million to nonprofits in the communities where its employees work and live. Its efforts have supported Habitat for Humanity, food banks, medical services, and much more. It's expanding its scope internationally, too, via disaster relief.

Weyerhaeuser, the forest-products giant, has contributed more than $215 million in the past 64 years, through its company foundation and its Weyerhaeuser Giving Fund. Like Albemarle, it does much of its giving in its company locations. It encourages philanthropy among its workers, and in 2011, 1,364 employees volunteered more than 21,000 hours. When company locations suffer disasters and the areas are declared official disaster zones, the company offers employees up to two weeks of paid time off (per year) to offer assistance.

FedEx focuses its giving on three areas that tie in well with the company: emergency and disaster relief, child pedestrian safety, and environmental sustainability. For example, it donated two air supply flights so that UNICEF could respond to famine in Somalia with food. Collaborating with various charities, it has delivered many tons of aid to poverty- or disaster-stricken regions. Its environmental efforts include growing its fleet of hybrid or electric vehicles by 18% in fiscal 2012, saving about 345,000 gallons of fuel.

Intel, through its Intel Foundation, has contributed significantly to education, empowering girls and women, and more. In 2011, 50% of its employees volunteered more than a million hours in their communities. That same year, employees and retirees donated $16 million to local nonprofits, with the foundation adding more than $10 billion to that. In 2010, Intel announced a 10-year, $200 million commitment to support math and science education.

It's smart to look beyond a company's philanthropy when evaluating it, but a generous company is likely promoting goodwill among its employees and customers, which could serve shareholders well. All of the above companies are impressive when it comes to philanthropy, as are many others. 

Earning well while doing good
Companies doing good, in their communities and beyond, can boost your portfolio's performance. And various other studies have suggested that socially responsible investments are at least competitive with the overall market, if not outperforming it on occasion. That's a solid motivation for even the most coolly rational investors to take social responsibility to heart. 

If you're in the market for solid socially responsible candidates for your portfolio, check out the real-money portfolio run by my colleague Alyce Lomax. Out of all the Fool portfolios in the group, hers was recently in first place.