There are various security oriented GNU/Linux distributions, they includes tons of hacking and cracking tools, most of them works command line, some of them have a GUI.
Do you know exactly how security experts / hackers uses these distros? Here the most common uses:
Penetration Testing (or pentest)
Includes Information Gathering Tools, Vulnerability Analysis and Exploitation Tools.
Tools that allows to examine digital media in a forensically sound manner with the aim of identifying, preserving, recovering, analyzing and presenting facts and opinions about the digital information.
Wireless Attacks tools
Tools for attacking wireless networks (eg. crack WiFi passwords).
Tools for files and folders encryption and decryption.
Stress Testing tools
Tools that perform stress test of a system (eg. multiple requests to a web site).
Sniffing and Spoofing
Tools to intercept (and manipulate) data that passes through the network.
Tools that allows to attack password protected files (documents, compressed archives, etc…) in order to retrieve decryption key.
Tools that allows Reverse engineering, the process of analyzing hardware or software and understanding it, without having access to the source code.
Tools that allows to attack websites: websites based on WordPress, Joomla and Drupal CMS, e-commerce websites and forums.
The tools allows perform vulnerability scans, and if vulnerabilities are found an attacker can use exploits to gain access and full control.
If you want try all these tools included in these distributions you can download the ISO images from the official sites and then burn on DVD or USB Drive.