Toolbox and essentials is kind of broad.
Ill just list what I always want around or may be helpful that hasnt been listed
Security
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
www.jasons-toolbox.com
Free online virus scans, in case you think your is corrupted..
1 housecall.trendmicro.com/
2
www.symantec.com/cgi-bin/securitycheck.cgi
3
www.pandasoftware.com/activescan
Im sure there are many more I missed
cool web shredder, used to remove coolweb that often blocks adware and spybot
http://www.spywareinfo.com/~merijn/cwschronicles.html
merjin made hijackthis and has many other good downloads
http://www.spywareinfo.com/~merijn/downloads.html
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
2
http://mvps.org/winhelp2002/hosts.htm
http://www.diamondcs.com.au/index.php?page=regprot
winsock fixes
fixes winsocks from bad bho's or removal of bho's
http://www.bu.edu/pcsc/internetaccess/winsock2fix.html
email security program; frontgate
http://www.net-integration.net/tools/frontgatemx.html
free av programs missed
AntiVer
www.freeav.com
Utilities
winrar
winrar.com, rar compression is better than zip files and win rar can handle all compressions while winzip cant.
hexed
hex editor, a must for anyone, free and a non programmer can use it to check files easily
driver cleaner
driver cleaner to remove left over installation files and registry entries from old installs, available from
www.driverheaven.net/cleaner
DX remover
Although it doesnt sem to support newest dx versions verywell it can delete them so you can reinstall.
Multimedia
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
VLC
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.
http://www.videolan.org/vlc/
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
renamer
rename files in batches, great for mp3s (id tag editor) and images
http://www.albert.nu/programs/Renamer/main.htm