These free tools have proven themselves for me and my clients. I hope you find them useful:
ActiveWords http://www.ActiveWords.com/ My favorite time saver - navigate, open, search using text vs mouse-miles traveled. I especially like the text substitution and integration with my Notes mail client. Check out this video on using activeWords to save time with Google/Gmail http://www.activewords.com/videos/AWforGoogle.html
Ninite – An easy way to get a bunch of free tools and install them all at once.
Ccleaner – Originally Crap Cleaner for windows
Search Everything – superfast file finder
Auslogics – Disk defragmenter (dont use on SSD disks)
FastStone Image Viewer 5.1 Freeware (Last Update: 2014-03-11)