Lol, I really have no life for actually making this topic. But I was really interested in quantifiying just how much of every season was filler and how much was plot, and it was fun doing it.

Note that all of these percentages are *approximate*, because I know that we could never get everyone to agree on all the criteria for filler and which episodes are or aren't. With some episodes its obvious, of course, but there are a lot that I think can be argued, even some that I debated with myself over including or not.

the Critera I used to determine plot vs filler was basicly the following. Filler episodes are episodes that do NOT contain at least one of the following things...

-Pokemon captures/releases/evolutions/trades
-events relating to gyms and gym leaders or contests
-scene where a character trains their pokemon to learn a new move or to signifigantly improve themselves in battle, such that the pokemon's progress is visible in later episodes.
-events involving signifigant character development or background information that gets refrenced later
-events the develop the rivalries between the main characters and their respective rivals
-episodes involving events, characters, or locations taken out of the games (this one would probably be the most controversial point)

so here they are.

-Indigo League: 82 episodes total. Approximately 26 fillers. Filler percentage: 32%

List of filler epuisodes
"The Path to the Pokémon League"
"The School of Hard Knocks"
"The Ghost of Maiden's Peak"
"The Flame Pokémon-athon!"
"The Kangaskhan Kid"
"The Bridge Bike Gang"
"Ditto's Mysterious Mansion"
"Dennō Senshi Porigon"
"Pikachu's Goodbye"
"The Battling Eevee Brothers"
"Wake Up Snorlax!"
"Showdown at Dark City"
"A Chansey Operation"
"So Near, Yet So Farfetch'd"
"The Purr-fect Hero"
"The Case of the K-9 Capers!"
"The Ultimate Test"
"Beach Blank-Out Blastoise"
"Clefairy Tales"
"Holiday Hi-Jynx"
Snow Way Out
"The Evolution Solution"
"The Pi-Kahuna"
"Make Room for Gloom"
"The Ancient Puzzle of Pokémopolis"
"Bad to the Bone"

(I struggled on wether or not to consider path to the pokemon league and school of hardknocks as filler. On the one hand, they really *don't* effect that much, but on the other, the AJ episode featured some character growth for Ash, plsu both AJ and Giselle appear in the 2nd opening, so obviously the writers remembered them.)

-Orange League: 36 episodes total. approx. 15 filler episodes. Filler percentage: 42%

List of filler episodes:
"The Crystal Onix"
"In The Pink"
"Shell Shock"
"Stage Fight"
"Bye Bye Psyduck"
"The Joy Of Pokémon"
"A Shipful Of Shivers"
"A Way Off Day Off"
"Wherefore Art Thou, Pokémon?"
"Get Along, Little Pokémon"
"The Mystery Menace"
"Bound For Trouble"
"Pokémon Food Fight"
"The Wacky Watcher"
"The Underground Round Up"

-Johto League. 158 episodes total. Approx. 79 fillers. Filler percentage: 50%

list:
"Roll On, Pokémon!"
"Illusion Confusion!"
"Flower Power"
"Spinarak Attack"
"Snubbull Snobbery"
"The Little Big Horn"
"Once in a Blue Moon"
The Whistle Stop"
"Ignorance is Blissey"
"For Crying Out Loud"
"Tanks a Lot!"
"Grin to Win!"
"Foul Weather Friends"
"The Superhero Secret"
"Mild 'n Wooly"
"Wired For Battle!"
"No Big Woop!"
"Tunnel Vision"
"Hour of the Houndour"
"Love, Totodile Style"
"Forest Grumps"
"The Psychic Sidekicks!"
"The Fortune Hunters"
"Type Casting"
"Fossil Fools"
Carrying On"
"Two Hits and a Miss"
A Hot Water Battle"
"Hook, Line, and Stinker"
"A Better Pill to Swallow"
Mountain Time"
"Wobbu-Palooza"
"Imitation Confrontation"
"The Trouble With Snubbull"
Ariados Amigos"
"Wings 'N' Things"
"The Grass Route"
"The Apple Corp"
"Houndoom's Special Delivery"
"All That Glitters!"
"The Light Fantastic"
"UnBEARable"
"Spring Fever"
"The Stolen Stones!"
"The Dunsparce Deception"
"The Wayward Wobbuffet"
"Sick Daze"
"The Poké-Spokes Person"
The Art Of Pokémon
"The Heartbreak of Brock"
"Doin' What Comes Natu-rally"
"The Big Balloon Blow-Up"
"The Screen Actor's Guilt"
"Right On, Rhydon!"
"The Kecleon Caper"
The Joy of Water Pokémon"
"Got Miltank?"
Fly Me To The Moon"
"Takin' It On The Chinchou"
Mantine Overboard!"
"Plant it Now... Diglett Later"
"Throwing in the Noctowl"
"An EGG-sighting Adventure!"
"Just Waiting On a Friend"
A Tyrogue Full of Trouble"
"Xatu the Future"
"Whichever Way the Wind Blows"
Some Like It Hot!"
"Hocus Pokémon"
"As Clear as Crystal"
"Same Old Song and Dance"
"Enlighten Up!"
Will the Real Oak Please Stand Up?"
"Wish Upon a Star Shape"
"One Trick Phony!"
"I Politoed Ya So!"
"Just Add Water"
"A Crowning Achievement"

(there are some episodes that it really hurts me to include on that list, like "Wired for Battle", since its like one of only three trainer battles Heracross had, and "Hook Line and Sinker" since it focused on Misty.)

Hoenn League. 132 episodes total. Approx. 39 fillers. filelr percentage: 30%

list:
"Taming of the Shroomish"
"You Said a Mouthful!"
"A Bite to Remember"
"Sharpedo Attack!"
"Turning Over a Nuzleaf"
"Ready, Willing and Sableye"
"Having a Wailord of a Time"
"Jump for Joy"
"A Different Kind of Misty!"
"Love at First Flight"
"Let Bagons Be Bagons"
"ZigZag Zangoose"
Maxxed Out!"
"Cheer Pressure"
"Going for a Spinda"
True Blue Swablu"
"Gulpin it Down!"
"Go Go Ludicolo!"
"Whiscash and Ash"
Me, Myself and Time"
"Pearls Are a Spoink's Best Friends!"
"Take This House and Shuppet"
"Lights, Camerupt, Action!"
"Crazy as a Lunatone"
"The Garden of Eatin'"
"A Scare to Remember"
"Judgment Day"
Clamperl of Wisdom"
"The Relicanth Really Can"
"The Evolutionary War"
"Training Wrecks"
Shaking Island Battle! Dojotchi VS Namazun!!)
Where's Armaldo?"
"Claydol Big and Tall"
"Beg, Burrow and Steal"
"Absol-ute Disaster!"
"Do I Hear a Ralts?"
"Showdown at Linoone"
Satoshi and Haruka! Heated Battles in Hoenn!!)
"Island Time"

(yeah, included the recap episode and the skipped episode in that)

Battle Frontier: 61 episodes total. Approx. 17 filler. filler percentage: 28%

list:
"Hooked on Onix"
"Rough, Tough Jigglypuff"
"Sitting Psyduck"
Hail to the Chef"
"Caterpie's Big Dilemma"
"Pasta La Vista"
"Fear Factor Phony"
"On Olden Pond"
"Off the Unbeaten Path!"
"King and Queen for a Day"
"Curbing the Crimson Tide"
"Three Jynx and a Baby"
"All That Glitters is not Golden!"
"Aipom and Circumstance"
"Strategy Tomorrow - Comedy Tonight!"
"Duels of the Jungle"
"Pinch Healing!"

Shinou League: 191 episodes. Approx. 34 fillers. filler percentage: 18%
list:
"Ya See We Want an Evolution!"
"Faced With Steelix Determination!"
"Cooking up a Sweet Story!"
"Drifloon on the Wind!"
"The Champ Twins!"
"Steamboat Willies"
"The Electrike Company"
Malice in Wonderland!"
(Satoshi and Hikari! Head for a New Adventure!!)
"The Keystone Pops!"
Bibarel Gnaws Best!"
"Nosing 'Round the Mountain"
"Luxray Vision"
"Sleight of Sand"
"The Bells Are Singing!"
"Arriving in Style!"
"Doc Brock!"
"Get Your Rotom Running!"
"Leading A Stray!"
"Cheers on Castaways Isle!"
"Hold the Phione!"
"Stealing the Conversation!"
"The Drifting Snorunt!"
(Mysterious Creatures: Pocket Monsters!)
"Beating the Bustle and Hustle!"
"Three Sides to Every Story"
"A Faux Oak Finish!"
Where No Togepi Has Gone Before!"
"Try for the Family Stone!"
"Sticking With Who You Know!"
"The Treasure Is All Mine!"
"Regaining the Home Advantage!"
(Metamon - Transformation Battle! Which One is the Real One!?)
(Goodbye Team Rocket! Love of Nyarth!?)

hahah. no wonder DP is the best season ever. Anyway, comments, discussion, opinions?

Edit: Removed "Air Time" from the johto list, since it fits with my 6th criteria (the radio station in Goldenrod was a game event). removed "Oh Do You Know the Poffin Plan!", from DP's list, because its the episode where Hikari learned to make Poffin, a skill she uses the rest of the series.

Edit: made changes based on some comments.

Edit: added "The Treasure Is All Mine!" to the DP filler list. Even though it makes refences back to "Holy Matrimony", I think in the end it didn't really change anything, either for the characters or in how the audience views the characters.