My recommended software

Desktop OS:
- Windows 7
- Windows XP

Server OS:
- FreeBSD 7.x
- Linux 2.6.x

Linux Distribution:
- Fedora
- CentOS

Mail server:
- postfix
- exim
- Microsoft Exchange 2007 (but not as an edge!)
- Microsoft Exchange 2010 (but not as an edge!)

Mail client:
- Mozilla Thunderbird
- Microsoft Outlook 2010

Media Center:
- Windows Media Center

EPG (for Israel):
- megaepg (not anymore! it hasn't been updated for years :()

Firewall software:
- ZoneAlarm

Anti Virus software:
- Kaspersky Anti-Virus 2012

Burning software:
- Nero
- ISO Recorder v3

Restoring software:
- Active@ Partition Recovery
- GetDataBack for NTFS
- EasyRecovery Pro
- NTFS Undelete (http://www.ntfsundelete.com/)

Disk management software:
- Partition Magic / Volume Manager
- GParted

Defrag software:
- Raxco PerfectDisk

IRCd:
- Bahamut

VoIP server:
- asterisk 1.4/1.6

Arcvhing software:
- 7-Zip
- WinRAR

Virtualization:
- VMWare ESXi
- VMWare Server
- Microsoft Hyper-V

Installation software:
- Wise Installation System (Professional Edition)

Remote connections manager:
- mRemote

Sniffers:
- SmartSniff (http://www.nirsoft.net/utils/smsniff.html)
- Fiddler (http://www.fiddler2.com/fiddler2/)

Password manager:
- KeePass (http://keepass.info/)