It's a tie between Mark 6 and Mark 45 for me.

On this list Mark 5, 6 and 45

But in general here are my favorite Iron Man and War Machine armors

Mark 39

How bout mark 46?

@Optimusprimebumblebee "Neo Astral-X" 123 those are basically all the Iron Man suits besides the iron legion

Mark 7 and Mark 17.

Mark 6 probably

I like Mark 6

Mark 21 shiny

Mark 6