i think i would cool to have all the seasons like summer winter fall etc. rain and snow(if i snows in Nevada) lol. more realistic like having to eat drink sleep. more houses. the game clock is longer so that 1 seconds isnt 1 minute in the game. it would cool to have something to carry all ur stuff around like a brahmin. a cover system for when in fire fights. better 3rd person movements cuz i thought 3 had kinda cheesy movements. u can get drunk if u down a whole vodka or have 10 beers n when u do jet u get high n if u take a lot u hilusinate(sorry i dont how to spell that). have a primary secondary some kinda grenade knife and have it shown on ur player. everything has weight including ammo that would make more realistic, but that has to go for enemys too. fix the glitches and the freezing from the DLCs!! better swimming.
i just named everything i could think of while i wrote so i know its a mess n not in any order but those r my ideas for NV. i also wrote also this off my ipod touch so sorry for spelling errors...

Half of those are covered by hardcoe Mode.

^This^ plus there is an ideas thread for stuff you want in New Vegas.

http://www.gamesas.com/index.php?/topic/1091732-what-do-you-want-in-new-vegas/