Pokemon Wikis, Databases, and Tools
serebii.net - My personal go-to for all things Pokemon, including news, guides, and game stats.
Bulbapedia - Good for reading about lore and trivia and finding official art.
Pokemon Database - Easy to access Pokemon Data and sprites.
pokencyclopedia - Excellent sprite resource.
The Spriters Resource - Another excellent sprite resource, mostly ripped by fans in sheets style.
pkmnclassic - Unofficial server to get online in Gen IV and V. Allows you to see what's avaliable on the GTS.
Going Online in Gen IV and V - Guide on how to get online in Gen IV and V, with a list of servers.
Living Dex Tracker
Entertainment
Pokecharms Trainer Card Maker
Shroomish Icon Maker
Video Game Music Downloads - With an account, you can make custom playlists and download entire soundtracks.
Random Pokemon Plush Generator
Pokemon Virtual Booster Pack
Pokemon Favourites Picker, by type and generation then it rounds up your all time favourites!
An elimination based Pokemon Favourites Picker
Let's Find Pokemon! FOUND
Affiliates and Other Sites
Affiliates
Dreamscape
Pamtree Berry - A fun site with minigames, tools, and collections!
Other Sites
Blue Moon Falls - Gen I and II resource and guides site.
Cave of Dragonflies - Large and rich fansite with resources and fun things to do.
Clover's Pokemon Village - A really cute and rich interactive website to explore.
Gamefreak Webpage Archive - A New site archiving things from old Gamefreak webpages, such as Ken Sugimori artwork.
Lugaw - Personal site
Mirage Island - Gen IV guides and other fun stuff
Newlamdda - I especially love the Pokemon Sprite Collage!
Sephiria - Personal Site
Stareon's Hideout - A sweet site with lots of fun puzzles!
TyranitarTube - My Favourite Poketuber, making gameplay and theory videos
Vault of Sky - Gen III/IV Personal Site