I decided to post a table of differences between the games and anime. Most are very obvious or nitpicky, but I'll post them anyway.
Heroes
Games (origin of stories): You name your character.
Anime: Ash Ketchum, and Gym Leaders Misty and Brock. In Hoenn, Misty is replaced by May and Max.
Brock and Misty
Games: Two Kanto Gym Leaders who appeared early, but not again.
Anime: Major allies of Ash.
Rival
Games: You pick the name of the rival in all but RSE.
Anime: Gary Oak.
Kanto rival's sister, Daisy Oak.
Games: Appeared in RBY, GSC, and FRLG. In the latter two, she'll groom one of your Pokémon for free. In FRLG, she'll also tell you how much one of your Pokémon likes you.
Anime: Not mentioned. Presumably, Gary is an only child. Daisy Oak is not to be confused with Misty's sister, whose name is also Daisy.
Father
Games: Mentioned while looking at a Super NES display in Celadon Dept. Store.
Anime: Mentioned early, and not again. Apparently dead.
Pokedex
Games: Records info on Pokemon seen or caught, though full info is obtained by catching. The main point of the journey.
Anime: Pokedex already has full info, and is just used to identify a Pokemon.
Silph Co.
Games: The main character must enter Silph Co. and defeat Team Rocket's plan, by exploring the place and finding Giovanni. You are rewarded with the Master Ball.
Anime: Not mentioned.
Rocket Hideout
Games: Rocket Game Corner in Celadon. Team Rocket must be run out of it.
Anime: Somewhere between Pallet Town and Viridian City, until Mewtwo destroyed it. Whereabouts of the current headquarters are unknown. Ash doesn't even go within seeing distance of the HQ.
Do the characters go to school?
Games: Instead of regular grade schools, there are specialized Pokemon Trainer's schools.
Anime: Not stated, but in the manga "Electric Tale of Pikachu," Gary says that Pokemon trainers automatically drop out.
Team Rocket's disbanding
Games: After defeating Giovanni in his Gym, he runs off after saying he has disbanded Team Rocket.
Anime: Team Rocket does not disband.
Feel free to post any additions or corrections.
Heroes
Games (origin of stories): You name your character.
Anime: Ash Ketchum, and Gym Leaders Misty and Brock. In Hoenn, Misty is replaced by May and Max.
Brock and Misty
Games: Two Kanto Gym Leaders who appeared early, but not again.
Anime: Major allies of Ash.
Rival
Games: You pick the name of the rival in all but RSE.
Anime: Gary Oak.
Kanto rival's sister, Daisy Oak.
Games: Appeared in RBY, GSC, and FRLG. In the latter two, she'll groom one of your Pokémon for free. In FRLG, she'll also tell you how much one of your Pokémon likes you.
Anime: Not mentioned. Presumably, Gary is an only child. Daisy Oak is not to be confused with Misty's sister, whose name is also Daisy.
Father
Games: Mentioned while looking at a Super NES display in Celadon Dept. Store.
Anime: Mentioned early, and not again. Apparently dead.
Pokedex
Games: Records info on Pokemon seen or caught, though full info is obtained by catching. The main point of the journey.
Anime: Pokedex already has full info, and is just used to identify a Pokemon.
Silph Co.
Games: The main character must enter Silph Co. and defeat Team Rocket's plan, by exploring the place and finding Giovanni. You are rewarded with the Master Ball.
Anime: Not mentioned.
Rocket Hideout
Games: Rocket Game Corner in Celadon. Team Rocket must be run out of it.
Anime: Somewhere between Pallet Town and Viridian City, until Mewtwo destroyed it. Whereabouts of the current headquarters are unknown. Ash doesn't even go within seeing distance of the HQ.
Do the characters go to school?
Games: Instead of regular grade schools, there are specialized Pokemon Trainer's schools.
Anime: Not stated, but in the manga "Electric Tale of Pikachu," Gary says that Pokemon trainers automatically drop out.
Team Rocket's disbanding
Games: After defeating Giovanni in his Gym, he runs off after saying he has disbanded Team Rocket.
Anime: Team Rocket does not disband.
Feel free to post any additions or corrections.