Kroger (NYSE:KR) is a large retailer with a market cap of about $24 billion. While it is commonly known as a grocery store, the chain also runs a number of department stores which sell other goods. Retail grocery stores may not be the most exciting stocks on the block, but they are good long-term value investments. And Kroger is proving to be a winner this summer.

Kroger's winning ways in the first quarter
Kroger reported that its first-quarter sales climbed by about 10% to $33 billion compared to the year-ago period. And drilling down on the good sales news shows that identical-store sales were up by 4.2% compared to a 2.9% rise in the first quarter of 2013. Moreover, net earnings were up to $501 million versus $481 million in the year-ago period.

Furthermore, Kroger recently announced a new share buyback program worth $500 million to replace its previously closed $1 billion share repurchase authorization. The retail grocer has a solid history of supporting shareholder value by way of share repurchases and dividend payouts. In this regard, Kroger announced a quarterly cash dividend of $0.165 per share. This will be payable on September 1, 2014 to stockholders of record on August 15.

Looking ahead, Kroger raised and narrowed its earnings guidance to a range of $3.19-$3.27 per diluted share for fiscal 2014 -- the original guidance had been for $3.14-$3.25 per diluted share. The grocer also raised its identical-supermarket sales growth guidance to 3%-4% for fiscal 2014 after an earlier forecast of 2.5%-3.5%.

Kroger continues to make moves that support share price growth, which is good news for investors looking for value. The company is a leader in the retail grocery sector and is well positioned to continue delivering solid earnings. In short, Kroger is a better value than its nearest rival Safeway (NYSE:SWY). Kroger may also be in a position to capitalize on the hard times that have recently befallen Whole Foods Market (NASDAQ:WFM).

Safeway's future is a matter of speculation
The big blip on Safeway's first-quarter earnings report was that earnings per share were a meek $0.06 -- a 62.5% cliff dive compared to the year-ago period. Moreover, the company is still working through its previously announced $9.2 billion buyout by Cerberus Capital Management -- which owns the Albertsons grocery chain, according to a recent Bloomberg report.

Safeway recently settled investors' lawsuits over the Cerberus deal. This will clear the way for a Albertsons-Safeway combination with more than 2,400 stores, 27 distribution facilities, and 20 manufacturing plants. If and when the $40 per share deal is done, the new and improved grocer could pose a challenge to Kroger.

But speed bumps remain in Safeway's parking lot that include a stipulation in the settlement agreement that requires it to sell off its stake in Mexican grocer Casa Ley. The Delaware courts must also approve the deal, and there is the uncertainty of an antitrust challenge by the Federal Trade Commission.

At this juncture investors need more than a crystal ball to see through the risk of these uncertainties, given the brave new world of regulatory oversight that has mushroomed during the last five years. In the meantime, Kroger will continue to build its top- and bottom-line growth while making shareholder friendly moves.

Whole Foods' share price hits a rough patch
Whole Foods Market's share price has been in the thick of it in part because of three straight disappointing quarters. The company has also lowered its guidance with each report.

The company last reported that in the second quarter its gross profit margin fell to 39.5% of revenue and earnings per share came in at $0.38. This was flat compared to the year-ago period. More importantly, Whole Foods reduced its guidance for the third consecutive quarter.

The company now expects sales growth of 10.5%-11% in 2014. Previous guidance anticipated a range of 11%-12%. It also reduced its guidance for earnings-per-share growth from a range of 7%-12% way down to between 3%-6%, and that led some investors to the self-checkout line.

Whole Foods has been met with growing competition from the likes of Sprouts and other regional organic markets that offer better prices for consumers. Whole Foods' share price is currently flirting with $38. With a forward P/E of 22.32, it will take a while for the share price to recover. Some investors with a long-term view might consider this a good entry point if the company penetrates markets abroad to revive its growth strategy.

The Foolish take away
In sum, Kroger represents the best value for investors compared to the still forming, new and improved Safeway and to a lesser extent Whole Foods Market. Kroger's stock has produced a return of 26% year to date and its shareholder-friendly buyback plan and anticipated revenue and earnings growth make Kroger a proven winner this summer.

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John Mackey, co-CEO of Whole Foods Market, is a member of The Motley Fool's board of directors. Kyle Colona has no position in any stocks mentioned. The Motley Fool recommends Whole Foods Market. The Motley Fool owns shares of Whole Foods Market. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.