I'm kind of surprised at the amount of people who said no for ammo crafting. Ammo crafting saves a lot of caps and the ammo types that you can create are extremely useful for different situations.
I mostly only convert between types, personally. Hunting shotgun loves slugs, so, dismantle 12 and 20 gauge buckshot and convert them to slugs. Or convert 5mm ammo into 5.56mm ammo for the LMG. Costs very little resources.
The only thing that I don't find extraordinarily important is campsite crafting (though the chems are pretty useful). The items that are required to make a lot of the recipes can be pretty rare and hard to come by and aren't really worth it. For example a bighorner steak requires a survival skill of 50 to make yet I can eat it without cooking it for no stat penalties. There's a lot of food available as well so why would I go out to find these hard to find ingredients when I could just go to a npc and buy some cheap food?
Cooked food gives *vastly* more HP. Seriously. With a maxed Survival, cooked foods make stimpacks look like aspirin. At 100 skill level the benefits are triple what you see without the skill, so, the unimpressive "desert salad" with all those hard to find ingredients giving 7hp per second? Now gives 21 (for 15 seconds = 315hp from one item). Cooked meat never goes off the menu, but the harder to make stuff is oustanding.
(I also got good mileage out of gecko skin curing. Golden gecko pelts are quite valuable!)
If you're playing on hardcoe, Survival definitely gets my vote for at least a moderate level of skill.