Since Halo 2, when they introduced the ability to play as an elite, I thought they could let us play as a flood. I think it would be really interesting in a regular slayer match to come across a spartan, elite, and a flood battling each other.
I would really want to see Sidewinder. I think that's what it was called. I had to have played on t hat one the most out of all of them. Even though they re-imagined it in H3 DLC, there were some similarities but not the same. I really hope to see t his map back.