Veaam Backup and Replication

Top Software!

THE CORPORATE STUFF

GFI EventManager
Provides event log monitoring to a central location, for both compliance and forensic analysis. It also will archive your event logs. Has a user friendly front end can be setup in no time at all.
GFI LanGuard
LanGuard has been around for years, I was using it over ten years ago! For network auditing, patch management and vulnerability scanning it's an excellent tool.
GFI MailArchiver
As more users want to use your messaging system as their own personal 'filing cabinet', and with the requirement for compliance, you need store all your emails. This provides an easy mail archiving solution, without the need for your users to have pst files all over the network!

THE FREE STUFF!

DESKTOP TOOLS
7Zip
Why pay for WinZip or WinRAR, this has better compression, can deal with the same formats, and can password protect your archives. In addition its quite happy to let you work with .iso images.
CD2ISO
If you have a CD that you need to turn into a .ISO file (either to upload somewhere, or for use on a VMware/Hyper-V server. This standalone executable file will convert any CD/DVD straight to .ISO format at the click of a button.
ImgBurn
I used to use Nero for all things CD/DVD burning related, but then Nero turned into a bloated pile of system resource hogging junk. Luckily a friend pointed me towards ImgBurn - it literally does jut what you want it to.
Double Driver
What a class piece of software! Sensibly backs up your drivers (And not ALL of them just the ones that wont be in your fresh Windows Install). It's freeware but I urge you to make a small donation to the developer.
   
NETWORK ADMINISTRATION TOOLS
mRemoteNG
One of the best bits of freeware I've ever found! If (Like me) you look after a lot of clients, servers, firewalls, switches etc, save all your administrative connections in one console.
WinAudit
PC Audit and Inventory software, Delivers a staggering amount of information, which you can save/email back to the office for inventory purposes.
   
SECURITY

ShrewSoftVPN
A x64 bit VPN client that works with Cisco ASA (More Info).

   
TROUBLESHOOTING AND REPAIR TOOLS
BlueScreenView
Great tool for analyzing BSOD (Blue Screen of Death) crash dumps, it will highlight what is suspects caused the crash.

Lockhunter I used to use Unlocker for this, but its not so sharp on x64 bit machines. Ever tried to delete a file/folder and been met with "Cannot delete Folder It is being used by another person or program" Install this then simply right click the offender and select "What's liocking this folder" to see what's holding it open, and unlock or kill the process.