This is the first version of useful CTF tools cheat sheets. I'm planning to update them with new useful tools.
Thanks to share for a good advice to add the links for tools. Here are the links to the tools from cheat sheets:

GDB - http://www.gnu.org/software/gdb/download/
IDA Pro - https://www.hex-rays.com/products/ida/support/download.shtml
Immunity Debugger - http://debugger.immunityinc.com/
OllyDbg - http://www.ollydbg.de/
radare2 - http://www.radare.org/y/?p=download
Hopper - http://www.hopperapp.com/download.html
nm - unix/linux tool
objdump - linux tool
strace - linux tool
ILSpy - http://ilspy.net/
JD-GUI - http://jd.benow.ca/#jd-gui-overview
FFDec - http://www.free-decompiler.com/flash/download.html
dex2jar - http://code.google.com/p/dex2jar/
uncompyle2 - https://github.com/wibiti/uncompyle2

Windows:
HxD - http://mh-nexus.de/en/hxd/
Neo - http://www.new-hex-editor.com/hex-editor-downloads.html
Linux:
Bless - http://home.gna.org/bless/downloads.html
wxHexEditor - http://www.wxhexeditor.org/download.php
Exe unpackers - Unpacking Kit 2012 - http://forum.exetools.com/showthread.php?t=13610

Wireshark, tshark - https://www.wireshark.org/download.html
OpenVPN - https://openvpn.net/
OpenSSL - https://www.openssl.org/related/binaries.html
tcpdump - http://www.tcpdump.org/
netcat - http://netcat.sourceforge.net/
nmap - http://nmap.org/download.html

OpenStego - https://www.openstego.com & https://sourceforge.net/projects/openstego/
OutGuess - http://www.outguess.org/download.php
SilentEye - http://www.silenteye.org/download.html
Steghide - http://steghide.sourceforge.net/download.php
StegFS - http://sourceforge.net/projects/stegfs/
pngcheck - http://www.libpng.org/pub/png/apps/pngcheck.html
GIMP - http://www.gimp.org/downloads/
Audacity - http://audacity.sourceforge.net/download/
MP3Stego - http://www.petitcolas.net/steganography/mp3stego/
ffmpeg (for video analysis) - https://www.ffmpeg.org/download.html

dd - unix/linux tool
strings - unix/linux tool
scalpel - https://github.com/sleuthkit/scalpel
TrID - http://mark0.net/soft-trid-e.html
binwalk - http://binwalk.org/
foremost - http://foremost.sourceforge.net/
ExifTool - http://www.sno.phy.queensu.ca/~phil/exiftool/
Digital Forensics Framework (DFF) - http://www.digital-forensic.org/download/
Computer Aided INvestigative Environment (CAINE) Linux forensics live distribution - http://www.caine-live.net/
The Sleuth Kit (TSK) - http://www.sleuthkit.org/sleuthkit/download.php
Volatility - http://code.google.com/p/volatility/

Text editors:
Sublime Text - http://www.sublimetext.com/
Notepad++ - http://notepad-plus-plus.org/
vim - http://www.vim.org/
emacs - http://www.gnu.org/software/emacs/

Cryptool - https://www.cryptool.org/
hashpump - https://github.com/bwall/HashPump
Sage - http://www.sagemath.org/
John the Ripper - http://www.openwall.com/john/
xortool - https://github.com/hellman/xortool

http://www.crypo.com/
http://www.cryptool-online.org/
http://rumkin.com/tools/cipher/
Modules for python - pycrypto - https://www.dlitz.net/software/pycrypto/