Retail giants Walmart (NYSE: WMT) and Costco (NASDAQ: COST) are recognized for offering shoppers bargain prices with a long history of generating massive shareholder returns. Despite different business models, both companies are having a record year with stronger-than-expected sales sending shares to an all-time high.

Retailers Walmart and Costco made robust stock repurchases months before their shares broke out to record highs in September.

Shares of Walmart have handily outperformed the stocks of Amazon and Costco, its two primary competitors, this year.

Costco (NASDAQ: COST) has been a big winner so far this year. Consumer staples stocks have generally had a good year, with the Consumer Staples Select Sector SPDR Fund (NYSEARCA: XLP) providing a total return of 15%.

Costco continues to post steady financial results, driven by its lucrative membership business model. Home Depot could see sales start to pick up as the Federal Reserve cuts interest rates. One of these stocks is the better buy based on the P/E ratio.