Je mettrais :
1. My brother is the best at odd jobs of all men I know.
2. This piece of music is the least musical of all I have ever heard.
3. This man is the strongest to climb high mountains I've ever known.
or This mountain is the hightest I've ever seen.
4. This is the worst actor of all times.
5. This woman is the most good-tempered of all I have met.