assuming portugal get out of the group, which is likely, they will face either Spain, Swiss, Honduras, or Chile...most likely either Spain or Chile. Obviously Spain would be a brutal draw so they would likely need to finish top of their group (means beating out brazil) to avoid them which tells me they don't have a great chance of getting to the quarterfinals, let alone the finals
Nigeria make an interesting longshot from a matchups standpoint because they have a fairly easy group and then would face a team from another easy group to get to quarterfinals. But they really don't have enough talent to make the finals so you'd be taking them in hopes of going for some guaranteed money if they could get to semis
Germany really have the easiest road. If they finish 1st in group they're likely to face USA or Slovenia in R16 which means they'll be in the quarters and I don't see any teams in A/B that would be favored against them. Same holds true for England except the 2nd placed team in group D (germany's group) would be a tougher opponent than USA or Slovenia. So I see either England or Germany in finals but, as 3rd/5th favorites, they are not an outsider of course.
In the lower half the only surprise would be if Spain AND Brazil fail to win their groups and play each other in KO stage which would open the door for Italy or Holland go be in the finals and both those teams are 10/1 or higher.
So right now I'd see much more value on Germany at 12/1 than on Portugal at 20/1 unless Portugal can avoid Spain in KO stage. If you wanted a super outsider I'd give Nigeria a shot at 100/1