The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find strong picks.Of these, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.In addition to the Zacks Rank, investors looking for stocks with specific traits can utilize our Style Scores system. Of course, value investors will be most interested in the system's "Value" category. Stocks with "A" grades for Value and high Zacks Ranks are among the best value stocks available at any given moment.One company to watch right now is Laboratory Corp. of America (LH). LH is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock holds a P/E ratio of 15.55, while its industry has an average P/E of 19.17. Over the past year, LH's Forward P/E has been as high as 16.41 and as low as 10.55, with a median of 13.54.LH is also sporting a PEG ratio of 1.47. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. LH's PEG compares to its industry's average PEG of 1.82. LH's PEG has been as high as 1.55 and as low as 1.04, with a median of 1.28, all within the past year.We should also highlight that LH has a P/B ratio of 2.60. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. This stock's P/B looks solid versus its industry's average P/B of 6.10. Within the past 52 weeks, LH's P/B has been as high as 2.94 and as low as 2.12, with a median of 2.56.Value investors also love the P/S ratio, which is calculated by simply dividing a stock's price with the company's sales. This is a prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. LH has a P/S ratio of 1.64. This compares to its industry's average P/S of 1.97.If you're looking for another solid Medical - Dental Supplies value stock, take a look at McKesson (MCK). MCK is a # 2 (Buy) stock with a Value score of A.Shares of McKesson are currently trading at a forward earnings multiple of 10.02 and a PEG ratio of 1.12 compared to its industry's P/E and PEG ratios of 19.17 and 1.82, respectively.MCK's price-to-earnings ratio has been as high as 11.27 and as low as 9.17, with a median of 10.04, while its PEG ratio has been as high as 1.73 and as low as 1.12, with a median of 1.41, all within the past year.McKesson also has a P/B ratio of -387.67 compared to its industry's price-to-book ratio of 6.10. Over the past year, its P/B ratio has been as high as 184.34, as low as -717.21, with a median of -105.23.These are just a handful of the figures considered in Laboratory Corp. of America and McKesson's great Value grade. Still, they help show that the stock is likely being undervalued at the moment. Add this to the strength of its earnings outlook, and we can clearly see that LH and MCK is an impressive value stock right now. Zacks' Top Picks to Cash in on Artificial Intelligence In 2021, this world-changing technology is projected to generate $327.5 billion in revenue. Now Shark Tank star and billionaire investor Mark Cuban says AI will create "the world's first trillionaires." Zacks' urgent special report reveals 3 AI picks investors need to know about today.See 3 Artificial Intelligence Stocks With Extreme Upside Potential>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Laboratory Corporation of America Holdings (LH): Free Stock Analysis Report McKesson Corporation (MCK): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research