Trigun & Trigun Maximum
From No Man's Land - A Trigun Wiki
Trigun & Trigun Maximum
Trigun and Trigun Maximum are the names given to the original Trigun manga, released between 1995 and 2009. The series ran for two volumes as Trigun (three if you're Japanese) and for 14 more volumes as Trigun Maximum.
Volumes
Trigun Trigun Maximum