looking over the fallout wiki just checking all of the perks from all of the fallouts I wondered if any of these (some would need tweeking and I'll suggest changes for some) could be added to add a little more flavor to the game and maybe make some fights last longer.
Perks
Hunter: ranks 1, Level 3, Outdoorsman 60. 50% more critical damage against animals and mutated animals. This perk will not affect animals such as Deathclaws/centaurs but will affect floaters as they are mutated flatworms.
Meltdown: ranks 1, Energy Weapons 150%. Foes killed by your Energy Weapons emit a corona of harmful energy 25% chance. When a target has its hit points reduced to 0 by an energy weapon, this perk will create a small explosion around the target, similar to a plasma grenade explosion, but smaller. A Meltdown explosion can cause critical hits and sneak attack criticals on nearby targets and propagate a chain reaction effect.
^Edit: upon a second look this perk would probably have to be merged with the Energy Charge perk which would allow you to overcharge your energy weapons, as for how this would be implemented would be up to the devs.
Quick Draw: ranks 1, Level 9, Agility 7. Equipping and holstering becomes 50% faster. ( I.E speeding up the animation of putting your weapon away/taking it out and switching it with the other slot, important for RT combat)
Regular Maintenance: ranks 1, Repair 120%(?). Slows the decay rate of equipment by 50%
Shotgun Surgeon: ranks 1, level 6, S.Guns 120%. When using shotguns, regardless of ammunition used(when other ammo types get in game), you ignore an additional 10 points of a target's damage threshold.
Super Slam!: ranks 1, Level 9, Str 6, Unarmed/Melee 80. Unarmed and melee weapon attacks have a chance of knocking down your opponent. (20%?)
Tough Guy: ranks 1, level 3. Reduced limb damage by 20%
Travel Light: ranks 1, level 6, Outdoorsman 45. 10% faster running speed when wearing light or no armor. (light armor being leather/combat leather jackets)(I don't think this one is possible without changing core game mechanics)
Center of Mass: ranks 1, S.Guns 90. you do an additional 15%(?) damage when targeting the torso. (but you actually have to aim shot the torso of the target) You don't fool around with fancy trick shots. Straight to the midsection and down they go.
Day Tripper: ranks 1. You've done enough chems to know how to hang on to the effects just a while longer. More specifically, ingested chems last 33% longer than they normally would.
Six-Shooter: ranks 1, Per 8. Revolvers cannot suffer critical failures, get +4 range, and get a +10 bonus on the critical table. You know that your trusty revolvers won't jam like those new-fangled automatic pistols. And hey, if you can't drop someone in six shots (or five), you need to spend more time at the firing range.
El Bandolero: ranks 1, int 5, level 12. You've been carrying guns and ammo all over the wasteland for quite a while now, and you're not a drooling idiot, so you know a thing or two about how to store it. All ammo weight for you is reduced by 50%.
Firewalker: ranks 1, EN 8. You have mastered the arts of walking on coals and taking cookie pans out of the oven bare-handed. For each level of this perk, you have +2 to laser/fire/plasma DT that stacks with armor.
In Your Face!: ranks 1, Melee 110 or Unarmed 110. Opponents can't make called shots with thrown weapons or firearms when you are within 1 hex and are only holding melee weapons or are unarmed. They also suffer a -10% penalty to hit with those weapons against all targets
Bigger They Are...: ranks 1, ST 6, Melee 120. Your attacks with melee weapons have a greater chance of knocking an opponent over. And when they are knocked over, they get knocked back farther. Double the knockback chance and distance for any melee attack (not unarmed). (don't forget you also knock them down)
Bulk Trader: ranks 1, Barter 120. Quantity is the name of the game, and you're holding all the cards. When you buy and sell goods, you get a better deal for larger quantities of a single item. (% based, how much idk)
Critical Defense: ranks 2, PE 6 AG 6, You've been battered around enough in combat to know when you really need to get out of the way. As a result, when an enemy scores a hit on you, their attack roll is effectively lowered by 10 points for purposes of determining critical hits.
Silent Running: ranks 1, Level 6, Agility 6, Sneak 50%. Now I know this is already in game but I think it should make it so that inventory weight is ignored but not armor weight or armor penalties. (would only work while wearing light armor)
*Scratched*(same as tough guy) Adamantium Skeleton: ranks 1, level 15. Limbs only receive 50% damage(this might be too high I would probably say 35%)
Gray Matters: ranks 1. Reduces head damage by 25% (maybe change this to 10-15%)
Swing For The Fences: ranks 1, level 9. +10 damage with Melee Weapons (not 10 static damage but 10 min & 10 max damage)
Bone Head: ranks 1,Level 6, ST 7. With this Perk, the chance of getting knocked unconscious is reduced by 50%.
Unbreakable: ranks 1, EN 8. Critical hits against your eyes, arms, legs, torso, and groin have to do 50% of your total hit points to achieve a cripple
Crazy Bomber: ranks 1, Level 9, IN 6, Traps 60%. Failures while using explosives are nullified (this includes grenades/missiles)
Drunken Master: ranks 1, Unarmed 60%, Level 3. +20% Unarmed skill / 5 AC while under the influence of alcohol.
Lead Foot: ranks 1, Level 3, Outdoorsman 60%, PE 6, AG 6. You gain 25% speed when behind the wheel on the world map.
Iron Fist: ranks 3, Level 4, Strength 4. +5 Unarmed Damage for each level of this perk.
Hit the Deck!: ranks 1, Level 4, Agility 6(should be modified), You react very quickly to the word "incoming!". Halves the damage from area attacks and splash damage. 50% less damage taken from area attacks and splash damage OR You're considered -3 hexes away (in any direction from you) from an explosion or spray when considering damage.
And one perk of my own.
Blind Zen: ranks 1, IN 7 LK 6. When blinded the player is never truly blind, through training by using his other senses the player can still sense where his opponents are. For every point of PE the player has the penalty for being blind is reduced by 10%. So if the player has say 7 PE then the aiming penalty is reduced by 70% incurring a 30% accuracy penalty but the player can not do aimed shots.