May was a disappointing month for many retailers, but McDonald's (NYSE: MCD) May sales figures show the Golden Arches continuing to buck negative trends. As the market's current volatility and uncertainty drive prudent investors to search for quality stocks at bargain prices, Mickey D's deserves a spot on their watch lists.

McDonald's same-store sales rose 4.8% on a global basis in May. Europe shone brightest, with a 5.7% increase in comps. U.S. comps rose 3.4% ,and the Asia Pacific, Middle East, and Africa segment rose 3.8%. Net sales increased 5.5%, or 6.2% in constant currencies.

Mickey D's pointed to the successful addition of Frappes to its McCafe offerings (look out, Starbucks (Nasdaq: SBUX)!) as well as Shrek-themed Happy Meal promotions.

Interestingly, McDonald's press release doesn't mention its voluntary recall of the 12 million Shrek glasses, whose painted illustrations contain cadmium -- albeit at levels well below those considered toxic. The company's shelling out $3 a pop to customers who return them, at an estimated total cost of around $15 million.

Compared to the recent high-profile PR disasters at companies such as BP (NYSE: BP), Goldman Sachs (NYSE: GS), and Toyota (NYSE: TM), though, McDonald's swift actions and willingness to take responsibility may emphasize why it's exactly the kind of high-quality company that Foolish investors should focus on these days. I say, forget the BP vs. Goldman argument -- covet a stock like McDonald's!

McDonald's did warn that the euro's weakness will crimp its net income for the full year. My Foolish colleague Tim Hanson recently outlined several companies with such dangerous exposure, including McDonald's, and offered good advice.

In the big picture, McDonald's has excellent management that has coaxed incredible operational performance for years on end, and its sales continue to thrill. Should short-term problems hammer the stock, Foolish investors could grab shares of this gold-standard blue chip at bargain prices.