The stock market finished 2023's first quarter on a strong footing with the S&P 500 up over 7% through the end of March. However, many stocks are still trading at relatively cheap valuations.

Three stocks that are trading at price-to-earnings multiples of less than 20 and are excellent income-generating investments are Verizon Communications (VZ -1.07%), American Express (AXP -2.74%), and Pfizer (PFE 0.88%). Here's a look at why these are among the best dividend stocks you can buy right now.

1. Verizon Communications

One of the best deals out there for dividend investors right now is Verizon's stock. At less than eight times earnings, the shares are trading well below their three-year average.

Chart showing Verizon's PE ratio falling since mid-2020.

VZ PE Ratio data by YCharts

Investors haven't been impressed with the company's results as its rivals have been reporting better subscriber numbers. But investors shouldn't underestimate its growth potential, particularly as it targets more business customers.

And while anticipated wireless revenue growth of 2.5% to 4.5% this year isn't terribly exciting, it's also not awful. The company's operations are still moving in the right direction amid some challenging economic conditions. Plus, with a payout ratio that's only 50%, the dividend isn't in any danger, either.

In the longer term, there's even more reason to be bullish. Under stronger economic conditions, there could be more growth as people upgrade their devices. As of the end of 2022, Verizon reported that 59% of its postpaid wireless phone customers had 5G phones.

Verizon's 6.7% dividend yield is incredibly high (the S&P 500 average is 1.7%), and long-term investors shouldn't pass up the opportunity to buy this top telecom stock.

2. American Express

You won't get a sky-high yield from American Express, but the credit card company is still a solid dividend investment. While its yield is a modest 1.5%, it's an excellent buy when combined with its resilient operations. Compared to its peers, Visa and Mastercard, American Express has enjoyed a superior growth rate in recent quarters.

Chart showing American Express's quarterly YoY revenue growth beating Mastercard's and Visa's since 2022.

AXP Revenue (Quarterly YoY Growth) data by YCharts

The company caters to a more affluent customer base, which could make it a safer stock to be holding right now. At 17 times earnings, this isn't as cheap a stock as Verizon, but it's still a great deal compared to the S&P 500 average earnings multiple of 18. And with American Express considered a top credit card for travel and performing better than its rivals, there's a lot of potential upside for the stock in the long haul.

It's also a popular Warren Buffett stock to own, so it has been vetted by one of the world's best investors.

3. Pfizer

Pfizer is another heavily discounted stock to own. It currently trades at just seven times its trailing earnings and 12 times its future profits. Investors have been wary of the stock given that COVID-19 revenue is going to decline in the years to come.

There's undoubtedly some risk here, but the healthcare giant has been using its cash and vast resources to seek out deals to pursue growth opportunities. It has closed on multiple deals within the past year, and it recently announced plans to acquire cancer specialist Seagen for $43 billion. This might not be the last of its deals

Despite all the wheeling and dealing, investors remain unimpressed as the stock trades near its 52-week low. For dividend investors, this could be a great deal. Pfizer's dividend yields 4%, and the company has been increasing its payouts aggressively over the past decade.

Chart showing Pfizer's dividend rising since 2014.

PFE Dividend data by YCharts

Pfizer has a pipeline that features 110 projects, When that's combined with its recent acquisitions, there's a lot of potential on the horizon for the business, which could help the company's impressive dividend rise higher in the future. This is another cheap stock that dividend investors shouldn't pass up right now.