Free Essential Hacking tools For every Hacker:

IP Tools:
IP-Tools offers many TCP/IP utilities in one program. This award-winning Free Hacking tool can work under Windows 98/ME, Windows NT 4.0, Windows 2000/XP/2003, Windows Vista and is indispensable for anyone who uses the Internet or Intranet.
It includes the following utilities
1.Local Info – examines the local host and shows info about processor, memory, Winsock data, etc.
2.Name Scanner – scans all hostnames within a range of IP addresses
3.Port Scanner – scans network(s) for active TCP based services
4.Ping Scanner – pings a remote hosts over the network
5.Telnet – telnet client
6.HTTP – HTTP client
7.IP-Monitor – shows network traffic in real time & many more
8.IP TOOLS has almost all the utilities built into it.So there is no need to use seperate tools for every indivisual process of hacking such as Port scanning,Whois scanning,IP monitor etc.It’s like a hacking tool kit which has all the necessary tools for hacking.
Download IP Tools Here

Cain and Able:

Cain and Abel (sometimes called simply "Cain") is a Windows password recovery tool. It can recover many kinds of passwords using methods such as network packet sniffing, cracking various password hashes by using methods such as dictionary attacks, brute force and cryptanalysis attacks. Cryptanalysis attacks are done via rainbow tables which can be generated with the winrtgen.exe program provided with Cain and Abel. Cain and Abel is maintained by Massimiliano Montoro.I have made a tutorial on Hack a Computer with Cain

 and able OR Download Cain and Able Here.

Brutus ( Password Cracker):
Brutus is a remote online password cracker for windows, good for HTTP,POP3,FTP,SMB,Telnet and lots others.. it's also free. It is available for Windows 9x, NT and 2000, there is no UN*X version available although it is a possibility at some point in the future. Brutus was first made publicly available in October 1998 and since that time there have been at least 70,000 downloads and over 175,000 visitors to this page. Development continues so new releases will be available in the near future. Brutus was written originally to help me check routers etc. for default and common passwords,I

 have also made a post on Brute force
Password Cracking explained alternatively

 you can Download Brutus Password Cracker Here

RainbowCrack:
A very nice Hacking tools.Its general propose implementation of Philippe Oechslin's faster time-memory trade-off technique. It cracks hashes with rainbow tables,

Features:
Full time-memory tradeoff tool suites, including rainbow table generation, sort, conversion and lookup
Support rainbow table of any hash algorithm
Support rainbow table of any charset
Support rainbow table in raw file format (.rt) and compact file format (.rtc)
Computation on multi-core processor support
Computation on GPU (via NVIDIA CUDA technology) support
Computation on multi-GPU (via NVIDIA CUDA technology) support
Runs on Windows XP 32-bit, Windows Vista 32-bit and Windows 7 32-bit
Command line and graphics user interface
Download Rainbow Cracker Here

LC5(LophtCrack):
Windows password auditing and recovery application L0phtCrack or LC5 attempts to crack Windows passwords from hashes which it can obtain (given proper access) from stand-alone Windows workstations, networked servers, primary domain controllers, or Active Directory. In some cases it can sniff the hashes off the wire. It also has numerous methods of generating password guesses (dictionary, brute force, etc). LC5 was discontinued by Symantec in 2006, then re-acquired by the original L0pht guys and reborn as LC6 in 2009.

Download LC5 here.

John the Ripper:
A powerful, flexible, and fast multi-platform password hash cracker John the Ripper is a fast password cracker, currently available for many flavors of Unix (11 are officially supported, not counting different architectures), DOS, Win32, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types which are most commonly found on various Unix flavors, as well as Kerberos AFS and Windows NT/2000/XP LM hashes. Several other hash types are added with contributed patches. You will want to start with some wordlists, which you can find Here. and

download  john ripper here.