Remaining unique type combos by introduction, SwSh

Generation I:

1. Poison/Flying
2. Poison/Ground
3. Ghost/Poison

Generation II:

1. Dark/Ice
2. Rock/Dark
3. Ice/Ground

Generation III:

1. Bug/Ghost
2. Rock/Grass
3. Ground/Psychic
4. Water/Grass

Generation IV:

1. Ice/Ghost
2. Grass/Ice
3. Water/Steel
4. Grass/Ground
5. Electric/Ghost
6. Poison/Fighting
7. Normal/Water

Generation V:

1. Normal/Grass
2. Ground/Electric
3. Ground/Dark
4. Rock/Fighting
5. Water/Ghost
6. Electric/Fire
7. Electric/Grass
8. Dragon/Ice
9. Dark/Steel

Generation VI:

1. Dragon/Fairy
2. Fairy/Flying
3. Electric/Normal
4. Steel/Ghost
5. Fire/Normal
6. Fire/Water
7. Rock/Ice
8. Rock/Dragon
9. Normal/Ground

Generation VII:

1. Normal/Dragon
2. Bug/Fairy
3. Fighting/Ghost
4. Fighting/Ice
5. Poison/Fire
6. Rock/Poison
7. Rock/Electric
8. Ghost/Fairy
9. Electric/Psychic
10. Ice/Steel
11. Ice/Fairy
12. Dragon/Fighting

Generation VIII:

1. Ice/Fire
2. Ice/Bug
3. Electric/Poison
4. Electric/Dark
5. Dark/Fairy
6. Poison/Fairy
7. Bug/Psychic

DLC:

1. Poison/Psychic

Edit (20.06.2020): Removed Galarian Zapdos's Fighting/Flying.
Edit (21.06.2020): Added Galarian Slowbro's Poison/Psychic. Removed Ground/Flying (forgot Landorus).