Some time ago, we decided to make a list of all "MUST HAVE" tools for a reversing environment.

Here is what came out.
We know there are many tools out there we haven't heard of, so feel free to suggest any other that it is not here.

This list is for Windows OS only.

Reversing Tools

• IDA Pro + cool plugins + IDC scripts + IDA python + IDA python scripts
• Immunity debugger
• Ollydbg + plugins
• windbg + symbols
• metasploit
• All sysinternal tools
• processhacker
• Red Gate .NET reflector
• syseye
• winapioverride
• spywindows
• Remotedll
• spystudio
• Deviare
• COMRaider
• Dranzer
• axman
• Explorer Suite
• Paimei
• Sulley fuzzing framework
• peach fuzzer
• Sniff-USB
• w3af
• The Volatility Framework
• Nirsoft tools (some of them are really useful)
• Runtime .NET object editor - this one or this one
• Memproof (dephi testing)
• HTTP Analyzer v5
• Wireshark
• The Art of fuzzing (toaf)
• nmap
• Scapy
• SoapUI
• WebInject

Development Tools

• python 2.5 & 2.6 + all external modules needed
• Any python IDE you like
• ruby
• Visual Studio + SDK Tools
• MinGW

Misc Tools

• VMWare
• GNS3
• IPython
• Console or Console2
• Notepad++
• Winhex
• Apache or some other webserver
• Firefox + plugins like firebug, HTTPFox
• Cygwin
• MySQL
• QTODBC
• WMI Explorer or WMI Tools
• ClipX (Extended clipboard, really usefull)
• Regex coach or any other regex tester
• WinMerge