Hmm... Mine were Ms. Word and PowerPoint 2003, Skydrive and PDF-XChange Viewer. I am still using all of them now even after graduating last year.
If I have to pick the most I relied on, I guess it would be Skydrive. I had a hard time to rely on flash disk, sometimes I would loss it on the lab and its size only 1GB. Skydrive also have integrated Office Web App, even though with limited functionality. So, thumb up for Skydrive .