HxD - HxD is a carefully designed and fast hex editor which, additionally to raw disk editing and...
IDA - The best-of-breed binary code analysis tool, an indispensable item in the toolbox of world-class software analysts, reverse engineers, malware analyst and cybersecurity professionals.
Malcat - Malcat is a feature-rich hexadecimal editor / disassembler for Windows and Linux for malware analysts, incident responders, CTF players and SOC operators.
Hex Workshop - Hex Workshop: Hex Editor, Sector Editor, Base Converter and Hex Calculator for Windows
PE-bear - PE-bear is a reversing tool for PE files.
Okteta - Okteta is a simple editor for the raw data of files.