Brazil, Germany, France, Italy, Spain, in that order. Germany's stock will go way up with Hansi Flick in charge.
England unlikely, Argentina and Portugal really unlikely. People are acting as if Belgium is out of chances, but the only players that are too old are their terrible defenders who should've been dropped long ago. Their best players are either in their primes or young.
Can United States make a run?
The United States probably is the best side in CONCACAF at the moment (especially if Mexico doesn't right the ship) but that doesn't mean much, really.
I'd put my money on Brazil, with Argentina (if Messi plays) or Portugal (if Cristiano Ronaldo plays) as the dark horses at this early stage.