Unpredictable enemy spawns. In New Vegas the same enemies are always in the same places. I know where they all are. I know what to expect. I can always avoid getting in over my head by avoiding certain places until I'm strong enough for them, and I hate it. Quests relying on certain enemies being in certain places is one thing, but New Vegas is just too predictable in this department.
I want to be surprised. I don't want to know what is lurking up ahead. I don't want to know whether or not I can handle what is coming up.
That is why I use the Endless Warfare mod, I'd post a link but the forum won't let me for some reason. It adds a much needed element of surprise to the enemy spawns. Now I can't be so certain about what I'm going to be facing.
Randomize the enemy spawns, that is what I want. I don't want to know what enemies to expect. I don't want to know if I can handle what is coming up.