As i can see, there will be no Emperor's Children (in near future, at last), so... Ave Dominus Nox.
Night Lords are fine too.

Iron Warriors all the way. No silly shenanigans, just cold steel.

Death guard all the way

Sons of malice,lol)
But Actually,there should be such legions as world eaters,death guard,thousand sons and so on.
(excluding Slaanesh's legions,which i wouldn't like to see)

A bit contradictory choice, but I'll probably an Iron warrior with an emphasis on Nurgle If deathguard isn't a choice.

From the depths of betrayal
Unto the fires of revenge
We are the sons of Lorgar
Bearers of the true word

Iron warriors all the way, Iron Within, Iron Without. Ferrum Fortis shall slay the forces of the false emperor.

iron warrior to destroy all the fortress.

I see the Night Haunter's boys are doing pretty good in this vote. Any reason why the Black Legion is lagging behind in this poll, all be it by under 40 votes.

Hard to vote when you have no arms