Southwest is my favorite airline. The end.
Well, I won't leave you hanging there. If you've never flown Southwest, you're missing out. The only reason I won't fly Southwest is they don't fly where I'm going, like earlier this year I had to go to Montreal, Canada and Kingston, Jamaica. Had to fly another carrier...oh well.
I love Southwest's No Assigned Seating policy. I love their idea of snacks -- we're talkin' REAL snacks, and as many as you want! They have the same beverage service as other airlines. The employees have a sense of humor, frequently making passengers laugh during their usually-mundane required tasks. I love that I can check in from their mobile app and print the boarding passes later, unlike some other airlines (some you can, but not all). And the seats are more comfortable, it seems like.
Love Southwest. All the time.