Would love to see a hardcoe Mode with basic needs (hunger, thirst, sleep deprivation), but I imagine as was the case with New Vegas, a mod will be required to give it some teeth, so you actually might die from starvation or dehydration if you're not careful.
(In the vanilla version of hardcoe mode in New Vegas, food and drinks were way too plentiful across the Mojave, and you only needed to sleep about once per week or so.)
My wishlist would include more varied visual effects for using chems/alcohol and some features from Arwen's Realism Tweaks like infections, food poisoning, craftable bandages, tourniquets, splints, blood transfusions, etc.
Some examples from the mod:
Spoiler - if you get hit, you develop a wound that you can't heal during combat.
- if you bleed out you start losing too much blood and you have to use bandages or a belt as a tourniquet to to slow down the bleeding or inject a stimpak into the wound (reduces your STR and can only be done outside combat)
- If you lose too much blood your carry weight goes down by 15 pounds. it can be treated by a blood transfusion
- If your wound infection level gets too high you start continuously losing health unless you treat it with antibiotics.
- If your left or right arm is crippled, you can't use rifles or 2-handed melee weapons.
- To treat fractured limbs you have to apply a medical brace for a period of time until it heals. For fractured skull or ribs, you have to inject morphine into the fracture. You can only use a doctor's bag if your medicine skill is high enough (I think 50).
- Eating food and drinking liquids does not provide HP.
- Eating uncooked food increases the level of bacteria quickly and if it exceeds a certain amount, you develop food poisoning
- While sick with food poisoning, you don't gain benefits from eating more.
Not a huge fan of the perma-death modes in games because either you rarely die, in which case the combat encounters feel too easy, or in my case, I die frequently and never make it out of the tutorial.