Living in the world of software, I paused to consider this question. I thought about my daily interaction with software and wanted to recognize and prioritize (in order to simplify) my top 10 applications.  So here they are listed in order of my use: 

1) Outlook 2007 on Windows Mobile 6 device - indispensible

2) Outlook 2007 - OWA or rich client - depending on where I am

3) Facebook on IE - we all have our vices

4) OneNote 2007 - particularly nice on my new tablet PC

5) Visual Studio 2008 - playing with F# now!

6) Notepad - I know, this one needs to any suggestions?

7) Word 2007 - writing my book

8) Excel 2007 - old habits die hard

9) WSS 3.0 - I like SharePoint, I wish the rest of the world would 'come along'

10) SQL Server 2005 or Katmai (CTP of SQL Server 2008) - it's all good 

What are your top ten?