The top 10 strongest characters in Gintama, based on the general consensus among the fans and the series:

1. Utsuro

2. Gintoki Sakata

3. Shouyou Yoshida

4. Oboro

5. Kamui

6. Kagura

7. Takasugi Shinsuke

8. Jirochou Doromizu

9. Housen

10. Abuto

Note that this list is not definitive, as the strength of characters can vary depending on the situation and context within the story.