In addition to what Burf says...7-Zip (for all your file compression needs)Launchy (get this and you'll hardly ever use your Start menu again)CCleaner (clean up all the temp files on your system, saving many MB or GB of space)Recuva (Recover deleted files. From the same people that make CCleaner)DAEMON Tools Lite (for mounting ISO images)ImgBurn (Use to burn CDs and DVDs)Handbrake (Use to convert all kinds of video files from one format to another)Pandora.com (Awesome app for listening to music. Not a stand alone application, it is web-based, but amazing anyway so I wanted to list)Picasa (Photo management with basic editing built in)Spybot Search & Destroy (Must-have tool for Spyware clean-up and prevention)Treesize Free (Great tool for discovering where all your space has gone on your hard drive)TrueCrypt (Use to create private encrypted containers on your HD, encrypt USB keys, or entire hard drives. Excellent utility!)WinSCP (Excellent SFTP, FTP, and SCP client)Stardock Fences (Really nice utility for organizing your desktop clutter)Pidgin (An all-in-one universal chat client)Teamviewer (Amazing remote access and remote desktop tool)Toodledo.com (Again, not an app, but a website. Awesome to-do-list application. One of the best I've ever used, and I've tried quite a few. Also has clients for multiple mobile devices) That's it for now. Those are some of my favorites that I always re-load when building a new machine.