Pokemon Yellow Version: Special Pikachu Edition
Bypass Cycling Road Guard
To get onto the Cycling Road without needing a Bicycle, simply hold Left while the guard warns you that you must have the Bicycle to enter Cycling Road. (If you already obtained the Bicycle, this still works if the Bicycle is in the PC.) In doing so, you will bypass the guard; if you continue onto Cycling Road, you'll still ride a bike.
Contributed By: KeyBlade999.
Have Pikachu instantly like you!
When you first start your game, you will have 1 potion in your pc that's in your room. Get it out. Continue playing the game untill you get Pikachu but haven't battled Gary's Eevee yet. Use the potion on Pikachu 5 times (even though it won't have any effect). Fight Gary and WIN. After the battle, when your Pikachu comes out of the Pokeball. He will like you.
Contributed By: PyroEnthusiast.
Get the Diploma
Complete your Pokedex (Mew is optional) and visit the game designer in the Celadon Mansion. He will give you a diploma as a reward.
Contributed By: infernohit.
Get through grassy areas without a single random encounter.
Once you've obtained the HM Cut you can use it to teach some of your pokemon the attack of the same name.
This ability now cannot only be used to cut down certain trees but also to get rid of any grass so you don't have to bother with any random encounters.
When saving and loading or leaving and reentering the area you used cut in, the grass will have returned.
Contributed By: KeeperBvK.
Pikachu's Beach Mini-Game
Use the Pikachu from your Pokemon Yellow in every match in the Tournament mode of Pokemon Stadium. Pikachu should learn Surf. Now go south of Fuschia City and into the house at the beach. Talk to the man inside. Make sure Pikachu is in your party. You should be able to play a mini-game.
Contributed By: All is Fair in Love and War.