This is a conservative list of mods for Fallout: New Vegas which I feel improve what's already there rather than changing it (much).
- Install xNVSE.
- Install FNV 4GB Patcher. I used to use FNV4GB but it prevented me from using ReShade. Even if you don't use ReShade this is probably still the better option as it simply patches the New Vegas executable rather than using in-memory patching via an extra executable.
- Install New Vegas Tick Fix.
- Install New Vegas Heap Replacer. Replaces the game's heap memory management system with a faster implementation.