Here's a set of good applications I use :
PAINT.NET - picture editing at it's very best for simple to mid-complexity photo editing tasks.
Microsoft Office 2007 Student (I've got a trial, planning to buy soon)
Office alternative : Ashampoo Office 2008 or Open Office
Essential PIM - free Personal Information manager (also available as portable USB edition)
ALZIP - free and fun to use archiver/unarchiver
see here
The entire suite of Windows Live applications : Messenger, Writer (blogging tool - VERY GOOD), Windows Live Mail, Windows Live Picture Gallery
I'm also using Yahoo Messenger - it's very popular here (Romania)
Web browser : Internet Explorer 64 bit version
Media Player : Windows Medias Player, iTunes and Winamp, also using VLC player for videos
Antivirus : BIT DEFENDER INTERNET SECURITY 2008