Investors interested in Utility - Gas Distribution stocks are likely familiar with UGI (UGI) and New Jersey Resources (NJR). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Right now, both UGI and New Jersey Resources are sporting a Zacks Rank of # 2 (Buy). This system places an emphasis on companies that have seen positive earnings estimate revisions, so investors should feel comfortable knowing that these stocks have improving earnings outlooks. But this is just one piece of the puzzle for value investors.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks that they believe are undervalued at their current share price levels.The Style Score Value grade factors in a variety of key fundamental metrics, including the popular P/E ratio, P/S ratio, earnings yield, cash flow per share, and a number of other key stats that are commonly used by value investors.UGI currently has a forward P/E ratio of 15.59, while NJR has a forward P/E of 21.67. We also note that UGI has a PEG ratio of 1.95. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. NJR currently has a PEG ratio of 3.05.Another notable valuation metric for UGI is its P/B ratio of 2.02. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, NJR has a P/B of 2.31.These are just a few of the metrics contributing to UGI's Value grade of B and NJR's Value grade of C.Both UGI and NJR are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that UGI is the superior value option right now.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 UGI Corporation (UGI): Free Stock Analysis Report NewJersey Resources Corporation (NJR): Free Stock Analysis Report To read this article on Zacks.com click here.