Toolbox and essentials is kind of broad.
Ill just list what I always want around or may be helpful that hasnt been listed
Jasons Toolbox, number ot tools to see whats running on a system from irc bots, open ports to a online check of your security settings and how to fix them. Also a test for email defenses and security
Free online virus scans, in case you think your is corrupted..
Im sure there are many more I missed
cool web shredder, used to remove coolweb that often blocks adware and spybot
merjin made hijackthis and has many other good downloads
hostfiles or registry entries to block malicious sites.
1 spyware guard or is it blaster, well the one that wasnt mentioned already, can be downloaded from the same site jaavacool
fixes winsocks from bad bho's or removal of bho's
email security program; frontgate
free av programs missed
winrar.com, rar compression is better than zip files and win rar can handle all compressions while winzip cant.
hex editor, a must for anyone, free and a non programmer can use it to check files easily
driver cleaner to remove left over installation files and registry entries from old installs, available from www.driverheaven.net/cleaner
Although it doesnt sem to support newest dx versions verywell it can delete them so you can reinstall.
klcodec mega pack
This is a must, it covers any codec available for multimedia, uses old versions of media player to view real player and quicktime files with out the bs, it also includes dvd, xvid,divx etc, since its origin is unknown to me, do a google for klcodec
videolan media player, can play anything, uses dx technology, small dl,
can play dat files in p2p programs and broken avi programs with no worry of scripts.
PSP, jasc software , best image editor for the price
winamp 3.0 or lower, awesome for online radio stations using shoutcast.com
TMPGENC, encoder for video editing
rename files in batches, great for mp3s (id tag editor) and images