giving me 20 linkers such on top of that having said that in colloquial English

Sure! Here are 20 common linkers used in colloquial English:

1. By the way
2. In addition
3. On the other hand
4. Furthermore
5. Anyway
6. To be honest
7. In any case
8. Nonetheless
9. In the meantime
10. As a result
11. Moreover
12. In a nutshell
13. Nevertheless
14. As I was saying
15. In the same vein
16. In conclusion
17. In my opinion
18. All things considered
19. As a matter of fact
20. To sum up

Note that these linkers can be used in various contexts and have slightly different meanings, so it's important to use them appropriately based on the situation