Please let me know via comment if you like to add something to this list.
Free Office Products
OpenOffice – Professional looking office suite that is compatible with Microsoft Office.
AbiWord – A free simple Word processor.
Free Management Software
Planner – Project Management software.
Dia – is a program to draw structured diagrams a replacement for Microsoft Visio.
OpenWorkbench – Desktop application that provides robust project scheduling and management functionality.
OrangeHRM – Human Resource Management.
FreeMind – Mind mapping software almost the same as PeopleSoft.
Free NotePad Software
Notepad2 fast and light-weight Notepad-like text editor with syntax highlighting.
Notepad++ is a free source code editor and Notepad replacement.
SciTE is a SCIntilla based Text Editor.
Free Desktop Publishing
Scribus supports professional publishing features. A good replacement for Microsoft Publisher.
BitTorrent Over 150 million users to deliver files to your PC faster than anything else. BitTorrent and µTorrent gives fast P2P file sharing.
PeerGuardian 2 is an IP address blocker that can prevent access to thousands of sites. Must have for P2P users.
Free Report Writer Software
JasperReports Embeddable open source Java reporting library, a replacement for Crystal Reports.
Free PDF Converter
CutePDF Writer (formerly CutePDF Printer) is the free version of commercial PDF creation software.
doPDF is a free PDF converter for both personal and commercial use.
pdfforge PDF Creator is a free tool to create PDF files from nearly any Windows application.
PDFCreator An open source PDF maker written in VB.
Free Antivirus Software
AVG antivirus By far the best!
Ad-Aware Malware Remover Great free Malware Remover.
Avast Antivirus Home Edition.
Anti-Vir Best detection rate of any of the freeware AV solutions.
Outpost Firewall Free gives you solid firewall protection with standard packet and application filtering to safeguard your data against unauthorized third parties.
M0n0wall is a project aimed at creating a complete, embedded firewall software package that, when used together with an embedded PC, provides all the important features of commercial firewall boxes.
Bitdefender Free Edition. It works perfectly. The only downside is that it doesn’t provide real-time protection.
Administrators and Webmasters
Nmap.org Network Mapper is a free utility for network exploration or security auditing.
UltraVNC is a powerful, easy to use and free software that can display the screen of another computer (via internet or network).
TightVNC is a free remote control software package.
Filezilla client and server FTP software.
hMailServer is a free e-mail server for Microsoft Windows.
YouTube Videos converted to PSP, Zune and iPods
Dvd Video Soft From this tiny application you can convert YouTube videos to watch on your portable devices. Point to the url and instantly convert YouTube video into PSP and iPod formats. Very Easy!
Organise and Edit Photos
Picasa is a Windows application that allows users to find, edit, and enjoy the pictures on their computer in seconds. Picasa also makes advanced editing and picture sharing simple with fast one-click fixes.
Gimp Free Image Manipulation Program.
Paint.NET free image and photo editing software.
Free Sound Editor
Audacity is free, open source software for recording and editing sounds.
Image and Video Capture Utilities
Jing instantly captures and shares images and video.
VirtualDub is a video capture and processing utility.
Jahshaka is a video and film compositing, editing and special fx system.
Avidemux is a free video editor designed for simple cutting, filtering and encoding tasks.
Personal Home Account software equivalent to Microsoft Money and Quicken Books
HomeBank use it to manage your personal accounts.
Grisbi personal accounting application.
jGnash personal finance manager.
Mint personal finance and budgeting online.
Small to Medium Business Accounting equivalent to Myob and Quicken
CurdBee web-based billing and invoicing application for Freelancers.
GnuCash personal finance manager.
TurboCash Open Source Accounting package for small business.
Free Engineering Software
KiCad is equivalent to Eagle software. Electronic Design Automation.