As was the case last year, not a single airline from Europe or the Americas made the overall top 10 list. That is something of a surprise considering Delta, like Qatar Airways, introduced a new all-suites business class last year. Also like previous years, the rankings are significantly skewed toward the Asia-Pacific region. This should not be a surprise considering the massive growth of aviation in that part of the world, which is only projected to continue increasing in the coming decades.
Depending on where you want to fly to in the USA will depend on the peak seasons. Due to the many, many states it can be hard to pinpoint exact months of the year to visit. Atlanta and Miami for example see the peak season from March to May and September to November. Las Vegas on the other hand is busy almost all year. You’ll find cheap flights to the USA if you go to Vegas during the Summer as temperatures in Las Vegas can get ridiculously hot. Once you’ve decided on a location in the USA you can start researching the peak seasons for that state or city and then secure cheap flights to the USA.
You're not crazy for thinking that a flight price has changed after searching it a few times in your web browser. Based on the cookies in your browser, flight prices do increase when a particular route is repeatedly searched, as the site wants to scare you into booking the flight quickly before prices get even higher. Always search for flights in incognito or private browsing mode to see the lowest prices.