Generations from good to less good (casually):
1. Gen 4
2. Gen 3
3. Gen 2
4. Gen 1
5. Gen 5
6. Gen 7
7. Gen 6

Generations from good to less good (speedrunning):
1. Gen 3
2. Gen 1
3. Gen 4
4. Gen 5 
5. Gen 2
6. Gen 7 
7. Gen 6