Group D to me is the most fascinating.
Argentina will still have the best player (arguably) in the world, but has struggled to qualify. That midfield is still a big question mark.
And then you got Iceland, who was a massive surprise in the Euros. Can they replicate it?
Nigeria is one of the top, if not the best team in Africa (let's go Alex Iwobi!). They will be a tough out.
And then Croatia is full of star power, especially on that midfield with Luka Modric, Ivan Rakitic, Ivan Perisic and Marcelo Brozovic (although they have Dejan Lovern on defence, that already makes it's very suspicious).
It will be interesting, this group. I don't think there's a clear favorite here, and every nation in this Group could win it.
Group F seems to be a tough group as well. I think we can expect Germany to be Germany, but the battle for the second placer spot could be really tough.
France has an easy group. Way too easy.