I have two favourite teams for the World Cup title from South America (Brazil, Argentina) and two from Europe (France, Germany) now. There are some teams like Belgium and Portugal too but I feel like none of them will make it to the title. The reason why I see Germany ahead of the other big teams I mentioned is that they are improving themselves again to start performing like in the old times. I see a big potential in them in this tournament and I will see if I'm wrong about them.
Each of the 6 teams you mentioned has the potential to be champions. And I guess any of these 6 teams will win the title. Germany, Belgium's gameplay is good enough. As a team they are able to play well. The Portuguese team is dependent on Ronaldo. If Ronaldo can play well, Portugal's chances of winning the title will increase. Argentina and Brazil teams are very strong. The team has a lot of star players. But I would say their match strategy is a bit weak.