Werewolves? Or Vampires?

Werewolves
Complete a quest for the Jarl of Dragonreach in Whiterun to begin your journey to lycanthropy. From there, drop by the Companions faction. They’ll give you a series of quests to complete. Finish every quest they give you until you complete the chain, and the Companions will send you on one final job. To gather some items before meeting them in the Underforge.In the Underforge, you’ll enter into the ritual to become a werewolf. Now, you’ll need to figure out where to find a cure…The benefits of becoming a Werewolf are; your health and stamina increase by 100, your sprinting speed becomes faster than a horse’s gallop. You gain a new shout that instills fear in enemies and summons wolves, while also gaining some hand-to-hand melee damage bonuses. You’re also a criminal, and will be hunted by guards while in werewolf form. There are drawbacks; you can’t use spells, equip items, or loot corpses in wolf-form. You also won’t be able to talk to NPCs. Your werewolf form will also scare away NPCs, or turn them hostile towards you. If you’re caught transforming into a werewolf, it’s counted as a major crime. Beware, you’re also weak against silver!Transforming into a werewolf is temporary, so the change isn’t permanent. If you do change into a werewolf, try to do it far away from civilization.
Vampires
Turn into a vampire! You can't handle being a vampire if you are not one in the first place. You can become a vampire by contracting the disease porphyric hemophilia, sometimes caught while battling vampires or other undead creatures. On Azura's Shrine quest (Level 2) you can do her quest and enter the cave since all of them are vampires let them hit you until you contract 'porphyric hemophilia' then finish the quest for a special reward or just leave. Another way to get it is to get pretty far in the "Dark Brotherhood" quests, up until you stop getting quests from Vincente. Ask him about vampirism, and of course say you want to be a vampire. He will bite you the next time you sleep in the sanctuary. This is the safest and most reliable way to become a vampire. If you don't want to kill someone to join the Dark Brotherhood, then a good way to get vampirism is to do the Gray Prince's quest in the arena. There are vampires in it, and if you don't get the disease - don't worry. Complete the quest, and the Gray Prince will become depressed. When it is time to fight him in the arena, he won't fight back. This will count as murder and allow you to enter the Dark Brotherhood, but will be completely legal. Once you've contracted vampirism you'll then need to know how to deal with it.