The following are the top ten best-kept cold-water fish I know:

1. guppy: strong adaptability and low water quality requirements.

2. Zebrafish: cold-tolerant, with wide feeding habits and strong reproduction.

3. angelfish: low water quality and easy to breed.

4. koi fish: Long life, beautiful appearance and strong disease resistance.

5. Goldfish: Fast growth and strong adaptability.

6. Rose crucian carp: low water quality requirements and strong reproduction.

7. Blue-cheeked sunfish: strong adaptability and strong reproduction.

8. Arowana: beautiful body and strong adaptability.

9. Tiger Sharpay: Good cold tolerance and fast growth.

10. Cold water butterfly fish: low water quality requirements and strong adaptability.

All the above cold-water fish species have the characteristics of strong adaptability, fast growth, low requirements for water quality and strong reproduction, and are suitable for beginners to breed.