Programs you couldn't live without?

I just discovered Synergy and it made my unix experience about 5 million times easier. Using a keyboard with a broken space bar and sticky keys sucked ass and transferring the peripherals is so seamless I'm astonished. To top it off, the configuration is probably the simplest I've ever encountered on a network program. If you have 2 computers, you cannot live without this thing.
http://synergy2.sourceforge.net/

There's also foobar2000, and with the foo_dsp_delta.dll Noise Sharpening plugin I basically can't listen to music any other way anymore.
http://www.foobar2000.org/
http://pelit.koillismaa.fi/plugins/dsp.php

xplorer2 - http://zabkat.com
Dual pane Windows Explorer replacement.  Not as pretty as the Explorer but decent enough looking dual pane layout.  Has Unicode support too.

Likewise, foobar2000 for audio playing.

FAR Manager
Winamp
My command-line tools and working environment (I should release them one day)

>>3
You mean your fuck-load of batch files?

Comic Display, mIRC, Winamp, and Media Player Classic

Artificial Girl 2

>>4

Perl and PHP scripts, actually. That way I can use most of them from Linux too, and the kind of stuff I do from them can't be done (easily) on CMD files. (As for Bash, the syntax sucks and the performance is terrible, I ain't coding for that.)

DUEL SAVIOR AND BALDR FORCE

does foobar have easy access volume contol yet?

It always did: global keys.

Kicks the ass out of anything else I've ever seen. Every player should copy that idea.

so then still nothing on its gui.