Due in no small part to lower gasoline prices, which leaves consumers of all income categories with more money to spend, US restaurants have been getting a significant boost in traffic and sales. Among fast food chains specifically, though, not all companies have been able to benefit equally. As burger giant McDonald's (NYSE:MCD) battles slowing sales, Sonic (NASDAQ:SONC) is managing to post consistently high comp sales growth. For its latest report, the company once again delivered excellent growth on both the top and the bottom line. Although the stock is expensive, it looks like the best pick in the drive-in space. After an easy beat in the first quarter of the fiscal year, Sonic once again breezed past estimates for its Q2 report. GAAP EPS of $0.14 doubled from last year's figure, beating estimates by $0.02 for the fastest growth rate in four years and the second consecutive quarter of increased profit growth. Read more