Deliverer (my favorite gun)

To get this awesome weapon you must go to the old north church and go down to the catacombs and after some ghoul fighting you will see a gold sign and you can turn and push it,to open the door spell the word rail road you will get confronted by these people called the rail road and then do the quest for them and in that quest you will get the gun.

The Shark Paint Job

In the atom cats garage in zeeks trailer is a magazine called shark schemes and it unlocks a cool paint job for your power Armour and it gives it a cool look.

Hot Rod Paintjob

There is a hut not far from the vault 111 and it was no enemies but inside there is a magazine called hot rodder and when you read it you get a cool as pain job.

Deathclaws

Deathclaws are the result of a pre-War experiment that involved creating a mutation of the Jackson's chameleon, along with several other species, to use as weapons on the battlefield. They are strong, agile predators that will attack the player character on sight. Their long and sharp claws are capable of inflicting great amounts of damage on the player character, sometimes deadly (hence their name).

Atom Cats Paint Job

To get the atom cats paint job you will need to go to the atom cats garage and you need to do a quest for them or tow but at the end you are able to buy the power armor or buy the paint job. 

Silver Submachine Gun

You get the quest for this gun in goodneighbor from a guy in the memory bank and he wants to recreate the silver shroud and sends you to a comic book store to get it.