I would like to see Colonel Augustus, General Chase Overcoat and Chinese Stealth Outfit. As far as weapons, I would like to see Pa's Fishing Aid.
The Chinese Stealth Armour as implemented was broken, so I personally think that there is no way it should be in New Vegas, unless the way it works is changed severely. Preferably it should have a limited duration per use, require energy cells to use or at least to recharge it. They could also add a chance of it shorting out depending on the enviroment you're in at that point, ie the damper/wetter it is the higher the chance of it shorting out.
As for the General Chases Overcoat, I would say that is location specific or in other words it should not be anywhere near New Vegas.
Other than that and back to the topic at hand, probably some of the 'standard' clothing outfits which were in Fallout 3 as those should be all over the country, although as others have mentioned elsewhere I'd prefer for there to be male and female versions of them and not the Fallout 3 polymorphic versions which changed depending on which gender your character was.