I hated Southwest and avoided them for years until they started offering nonstop flights from San Diego to Chicago. Given the other carriers have fewer nonstops (if any) on that route, I usually fly Southwest. I always pay the $15 for early bird check-in (get assigned to the "A" boarding group) and upgrade to Business Select at the airport (typically get position A5 or 6) which usually gets me my favorite seat on a 737 - the one behind the wing exit door. You see, the row next to the wing exit has two seats, not three, so my long legs can stretch as far as they please. For me, their seats are no more or less comfortable than the other carriers'.