What mods you used with NV? In my opinion it's a great game straight out the package and the only mod I'm planning to use on my next game is some UI mod, and maybe some graphical improvements.
Unlike say Oblivion that needs a truckload of mods before I could enjoy it.
I have over 30+ mods installed with everything from simple terrain fixes to advanced game altering mechanics.
Here are some of the most popular.
Enhanced blood textures (which make blood splatter look quite realistic)
Electro City (which combined with darker nights make the wasteland a cool place to exlpore)
Neveda Skies (adds sand/electric/radioactic and thunder -storms, and makes the sky look truely beautiful - it also makes NPCs run for cover when storms come)
Populated Casinos (which makes the Strip come alive)
Realistic Portable Tent (My favorite - it adds a personal tent that takes some time to set up, you decide how long, which is worn like a backpack)
Project Nevada (which makes helmets, glasses and headgear restrict or enhance your sight and gives the game a more FPS feel with a reactive crosshair)
More Perks (which adds a few dozen new perks that make sense within the setting)
Bounty Hunter (fully voiced quests where you hunt down some of the worst scums of the Wasteland)
Real Time Settler (allows you to build your own village, where you scavenge for resources, cut down trees etc and try to keep order and food production high)
All in all I try to choose mods that make sense to the setting instead of those that add Space Marines and naked foxes.