"Gunslinger" Archery 50: Guns do more damage.
"Get Some Daggers" Two Handed 50: When you have a two handed weapon equipped, your daggers do more damage.
"I'm Sworn to Carry Your Burdens" Speech 30: Not ONLY is Lydia sworn to carry your burdens. Any other follower is too! They even say the phrase!
"Where'd This Come From?" Smithing 15: Every time you smith, upgrade, tan, or smelt an item, an iron dagger appears in your inventory.
"Water Finder" Lockpicking 15: You'll find more water jugs in containers.
"Trolololol" One Handed 60: When you kill a troll with a one handed weapon, you'll find a troll skull in its inventory.
"Trolololol x2" Two Handed 60: When you kill a troll with a two handed weapon, you'll find TWO troll skulls in its inventory. If people ask where the second one came from, tell them its a friend's.

Ugly: No one will marry you. Intimidation is 50% more effective.
Sweet Tooth: Any food you loot is transformed into a sweet roll.
Amnesia: Lose all perks, learn skills 50% faster.
Sammich: Once a day, summons your spouse, with tasty sammich in hand.
(Female Only) What lovely...eyes you have: Persuasion bonus while wearing Tavern Clothes or Forsworn Armor.
Black Widow: You inherit 400% more money when your spouse dies.

Clean & Tidy: Your character will clean his or her boots on a doormat before entering a house/castle/fortress. (Animation not skippable.)

Speech: "Animal Whisperer" - Can now have a conversation with any animal.
Alteration: "Mudcrab Lover" - temporarily transforms target into a Mudcrab.
Speech: "Useless Begger" - can beg one septim from any friendly NPC.
Pickpocket: "Skooma Fiend" - everyone now has one skooma in their inventory to steal.
Alchemy: "Too much Nirnroots" - eating a Nirnroot will now make you glow in the dark at night, while giving off a distinct humming sound alerting all enemies in the vicinity
Pickpocket: "Bastard Thief" - placing a stolen item into your target's inventory will cause all guards in the area to arrest and/or attack that person.
Armorer: "Manliest Smith in Skyrim" - smithing while unclothed will improve the created item by 10%.

Conjuration - Infernal Regeneration "Your summons regenerate health 20% more faster"
Speech - Beastmaster "Persuasion is 20% better with female beast races"

I would also like to say that the point of this thread is not to make perk that cause harm to you, instead the idea is to make perks that are hilariously useless, such as

Beer Goggles: With this perk, whenever you drink an alcoholic beverage, your vision becomes blurred, your speech slurred, and your pants have a 25% chance of going missing.

Anything with Magicka regeneration.

"Free fries friday" - Get free fries at burger king today

"It's bad for my karma, man" : All food replaced with vegetarian option, wildlife kills cause 10% loss of combat damage due to guilt, bunny kills may affect entry into Sovngarde...

Conjuration Perk: Decrease walking speed by 50% and increase lockpicking skill by 25 while any restoration spell is in use.
Two-Handed Perk: Increase destruction damage by 150% while dual-wielding.
Sneak Perk: Increases the chance of being seen while sneaking.

Not sure about useless, but would be interesting.

Drug addict: double all positive effects from drugs (skooma, moon sugar, ect.) If gone without for 24 hours the screen goes all blurry and you randomly stagger.

Speech 100 world shaper: gain extra options in social interactions as well as paths in quests. People also start talking about and noting your achievments.

MEME- You now do 10x damage when shooting arrows to the knees.

Reset Perks: Because you were to stupid to read about the perks the first time

two-hand: the target absorbs as much health as you take away

archery: arrows explode when drawn.

Speech: Messiah perk, makes the whole city follow your every move

Alteration: Downsize perk, Can turn a Grand Soul Gem into wooden bowl

Weakness to boogey, its worse then getting hit by ice spike, causes the target not to paralyse but to boogey, duration depends on skill level of caster

Conjuration: Bound heavy clown suit

Active effect: Black-eye perk, Your housecarl punches you in the face while you sleep

There is already one in game. The final heavy armour perk "reflect blow" blows, really hard.

Water Mage: Your spells are 50% more effective when cast underwater.

Horsemaster: Your horse recovers stamina 25% faster.

Mask Mastery: Your armor boosting spells are improved by 5x if you're wearing a Dragon Priest mask and are unarmored.

Cold Tolerance: Your character can survive in freezing conditions so long as they are natural.

A True North perk. You would get text telling you that you think are facing north whenever you face north.

A True Nord perk. You get simplified dialogs with bigger fonts for the subtitles and the NPC speaks 50% slower.

The first lockpicking perk.

Illusion. Mixed casting. Allows you to combine effects like candlelight and invisibility....

lulz

Perk Confirmation: Choosing this perk will give you confirmation you are able to choose perks.