Wondering who to take your next cross-country flight with? Which major U.S. carriers are hot, and which are not? When figuring out the best U.S. airlines, personal experience is important, but so are cold, hard statistics.The Wall Street Journal recently published its list of best and worst U.S. airline companies, grading them on seven “equally weighted operations metrics”: on-time arrivals, flight cancellations, extreme delays, baggage handling, tarmac delays, involuntary bumping, and complaints.