This is going to be a guide for all users as a reference to find notable NPC's, or places, or even events faster!
Let's create a guide together so that if we were to look for something in the main game series such as the Hidden Power person, we'd know where to find them and their location and stuff! Some of the things listed might be dailies, but there can also be stuff like the Heart Scale person and stuff. Please comment or answer to help add to the master list that I'll put down below so everything is easier to look for, but of course leave your answer so that it can at least be up-voted for having credit for contributing to this guide! It might need a lot of work, cause I am planning to cover ALL games with events (games like the Generation I & II games are ones where I have no knowledge of for example!) which is why I am asking all of you to help us all out!
. Use the shortcuts CTRL + F (Windows users) and Command + F (Mac users) to search for specific NPC's or places.
. If you are editing this, please try and keep it neat and descriptive enough to understand!
I will list the stuff I can remember for now and stop blabbering and taking up space at the top:
Pokemon Red and Blue
-Name-rater: Lavender town.
Pokemon Yellow (Special Pikachu edition)
-Name-rater: Lavender town.
Pokemon Gold and Silver
Pokemon Fire Red and Leaf Green
Pokemon Sapphire and Ruby
- Name rater man: The name rater that is able to change your Pokemon's nickname (as long as it is under your Trainer ID) is located in a house to the west of the Pokemon center in Slateport City.
- HM locations:
. Cut: Talk to the woodcutter man in a house to the west side of Rustboro City.
. Flash: Talk to a frightened man in Granite Cave in Dewford Cave.
. Surf: After defeating the gym battle with your dad (Petalburg City), and Wally's father will reward you with it.
. Rock Smash: Talk to a man in a house in Mauville City.
. Strength: Break the rock in the cave next to Verdanturf Town using Rock Smash so some dude and a girl can rejoice, and he will reward you with the HM.
. Waterfall: You will receive this HM by speaking with Wallace in Sootopolis City after the scene when Kyogre and Groudon stand there.
. Dive: You will receive this HM after a battle when you team up with Steven in the Space Center when it is overtaken by Team Magma.
. Fly: You will receive this HM after a battle with May near the Weather Institute next to Fortree City.
- Hidden power type checker: A man in the Game Corner prize building in Celadon City, there will be a man that tells you what type your Pokemon's Hidden Power is.
- Shoal Cave tides:
. Low tide: 9:00 am to 3:00 pm and 9:00 pm to 3:00 am
. High tide: 3:00 pm to 9:00 pm and 3:00 am to 9:00 am
- Name Rater guy: He is located in a house to the west of the Pokemon center in Slateport City.
- Daily Lottery: Go to the department store to the north of Lilycove City and speak to the attendant on the first floor to participate in the lottery based on your Pokemon's trainer ID's.
Pokemon Diamond and Pearl
- Move re-learner: Trade a Heart Scale to re-learn a move; he is located in a house to the right of the Pokemon Center in Pastoria City.
- HM locations:
. Cut: Cynthia gives it to you in Eterna city after you beat Gardenia.
. Fly: In the Team Galactic Warehouse in Veilstone city.
. Surf: Cynthia's Grandma gives it to you in Celestic town.
. Strength: When you go to Iron-island a lady who is blocking the cave gives it you.
. De-fog: The Solaceon ruins at the bottom.
. Rock smash: A hiker in a cave in Oreborough city gives it too you after you beat Roark.
. Waterfall: Jasmine gives it to you in Sunny-shore city after you beat Volkner.
. Rock climb: On route 217 near a house use the dowsing machine to find it.
- Name-rater: Eterna city in one of the big buildings.
- Hidden-power type checker: Veilstone city in the building where you redeem coins.
- Daily-lottery: Jubilife-city in the TV station building.
- Move-tutors: 1 in the Pastora city swamp, 1 in Snowpoint city, 1 on a mountain right above the Battle Area.
- Move-re-learner: in Pastora city south-east of the Pokemon-center.
- Move-deleter: Canalave city just south of the Pokemon center.
* Due to an 8000 character limit on a question, I will split Pokemon Black/White and Pokemon Heart Gold/Soul Silver in two separate answers to this question.
If you have some additions to the Pokemon B/W/HG/SS games, comment on those answers, but you can still answer this question for suggestions to the other games.