I don't personally use the
JSawyer mod, but a lot of people generally regard it as the "director's cut" of NV. For one-stop rebalance shops, there's also
FNVGO, but it's still under development, with only the very early game fine-tuned beyond the general gameplay tweaks.
For myself, I like to gear my NV towards what I tend to refer to as a "poor man's tactical shooter". This uses a base of
JAM for base functionality and the now-deleted
Solid Project for more advanced features like animated stimpack usage. There's also the option of
Project Nevada, which has been largely superseded by JAM, but carries a number of supplimental modules that you might or might not be interested in. The good part is that all three of these play together very well as long as you fiddle with them in the mod manager to make sure that you aren't running multiple versions of the same function.
For actual combat values, I run
Realistic Weapon Damage, which can be tempered with
BLEED to make something a little less instantly deadly, but still leaves the door open for "boom, headshot" to happen. If you really want to fuck your shit up, grab
No Pip-Boy in Combat, and learn to love the hotkeys.
For NPCs, I recommend either
Unforgiving Combat or
Enemy AI - Tactics, combined with
NPCs Can Miss if your eyes are glazing over at the thought of how I can play like this.
Finally, on the "feel" side of combat, a run a smorgasboard of little mods like
GBMM,
Realistic Lead,
More Realistic Aiming,
Real Recoil, and
Collision Meshes. Finally, I top it all off with the
Asurah Reanimation Pack for 1st-person animations, the
Weapon Animation Replacer for 3rd-person animations, and
Slow Death for littering the battlefield with the dead
and dying.