When thinking of Spaghetti Westerns the name at the top of the list is Sergio Leone. Rightfully so as he has made some of the greatest in the genre. Heck some of them I would consider the greatest of any genre. But there is a Sergio not far behind. Corbucci has put out numerous good ones including 2 of the best in Django and The Great Silence. The latter of which I think is a top 5 Western ever made.

If you are into Westerns and haven't seen some of his I highly recommend you do so. Other Westerns besides the big 2 Django (1966) and The Great Silence (1968) include the following.

Massacre at Grand Canyon (1963)
Minnesota Clay (1964)
Johnny Oro (1965)
Navajo Joe (1966)
The Hellbenders (1966)
The Mercenary (1968)
The Specialist (1969)
Companeros (1970)
Sonny and Jed (1972)
What Am I Doing in the Middle of a Revolution? (1972)
The White, the Yellow, and the Black (1974)