Investors looking for income have had few choices in recent years as interest rates have stayed close to zero.

Now, of course, to fight the COVID-19 pandemic, the Fed has lowered rates to zero, making stocks the only opportunity for yield-seeking investors.

Dividend investing is more popular than ever right now. But not all dividend stocks are worth owning. Today, we're separating the weak from the strong to show you only the best dividend stocks to buy in June.

As crucial as dividends are, the cash payout is not the whole story. Stock buybacks are another way of handing cash back to shareholders. Buybacks reduce the number of shares outstanding, making each remaining share more valuable. Add up the dividend payout, and the percentage of the outstanding shares retired gives us the total shareholder yield for a particular company.

Research has shown that considering the total shareholder yield can result in higher total returns. Since 1981, portfolios of those large-company stocks that have the highest shareholder yield have trounced the S&P 500 index and a portfolio comprised of the highest dividend-paying S&P 500 companies.

Looking at the top shareholder yield stocks today uncovers some exciting ideas right now. Here are the three best dividend stocks today…

Best Dividend Stocks to Buy in June, No. 3: MetLife

MetLife Inc. (NYSE: MET) had a strong first quarter, but they inevitably face some headwinds from the zero-interest-rate environment. At the current price, all of the potential short-term difficulties appear to be priced into the stock right now as the stock is trading for less than five times earnings and below half of the company book value.

MetLife has a strong record of rewarding shareholders. They have raised their payout every year for the past eight years. From 2007 through 2012, they held the payout steady to conserve cash in the wake of the financial crisis. The most recent increase was in April of this year, as the payout was hiked by 4.5%. The shares currently yield about 5.5%.

They also buy back a lot of stock. For the past three years, they have reduced the share count by right around 5% a year.

Add it all together, and you have a total shareholder yield north of 10%, one of the highest among all high-quality blue-chip stocks right now.

Best Dividend Stocks to Buy in June, No. 2: Corning

Corning Inc. (NYSE: GLW) makes optical fiber, glass substrates for liquid-crystal display panels, and specialty glass and ceramic materials. In English, that means they are essential to the data centers popping up around the globe and the material that makes up the screens on which all that data is displayed, including your smartphone. Its patented Gorilla Glass is in every model of a high-end smartphone, including every variation of the iPhone.

Corning's environmental technologies segment produces ceramic products to reduce emissions, especially in cars and trucks.

Corning will be impacted by almost every powerful new trend over the next decade and see fantastic earnings growth.

Corning is another blue-chip shareholder yield champion with a dividend yield of 3.63% and a buyback rate of over 6%.

But our best dividend stock does it one better…

Best Dividend Stocks to Buy in June, No. 1: Walgreens Boots Alliance

Walgreens Boots Alliance Inc. (NYSE: WBA) is one of the few retailers that will probably see an increase in sales and profits during the pandemic. While there have been some minor supply chain disruptions, Walgreens stores worldwide have stayed open to serve their customers. Prescriptions don't stop getting filled because there is a crisis. They may have seen more drive-through activity during this time of social business and economic slowdown, but they have still filled all those orders.

Walgreens should also get a boost from the in-store and drive-up coronavirus testing it started offering fairly early in the crisis. Longer-term sales will be driven even higher buy the aging population.

The company has a cash yield of over 4.5% and a buyback rate of over 6%. Walgreens is another double-digit shareholder yield candidate for your income portfolio. Walgreens has also been consistent with dividend increases, and the average increase over the past five years has been over 6%.