Here are some bits of software I use.
Many of them are free, but some require a registration fee (shareware).
If you download a shareware application and find that it's useful, please please please pay the author.
jEdit is a very good, cross-platform text editor.
It loads quickly, has a pretty good interface (it _looks_ like a java app, but it's not bad).
It's very configurable, including syntax highlighting, macros, and lots of options.
What more can I say? It's cool. I use it. Still, I'm always on the lookout for something better:
a good text editor is an absolutely essential tool.
I use it for HTML, SQL, ASP, awk, csh, ksh...
It has a good macro language (beanshell, which is essentially a java interpreter), and a nice plugin architecture.
There are lots of plugins, many of which I use regularly.
Freeware
Open source competitor for MS Office.
Has word processor, spreadsheet and presentation software.
I've only really used the presentation part so far.
It's cool.
I don't think you can do quite such nifty stuff as you can with Powerpoint, but for me it's way good enough.
A particularly nice feature of all the apps is that you can export directly to PDF.
(http://filezilla-project.org/)
Excellent little FTP client. Flexible. Usable. Nice.
Also supports SFTP.
Freeware
This may sound slightly esoteric, but when you need it, you need it.
Wireshark is a snooper or port-watcher. It logs all the data sent/received by your PC to/from the network.
You can filter to look at a specific port, or traffic to/from a particular IP address.
Wireshark used to be called Ethereal
Freeware
(http://www.chiark.greenend.org.uk/~sgtatham/putty/)
Telnet client. Supports secure shell (SSH). also has secure REXEC and secure FTP clients.
Essential if you're hooking up to secure hosts.
Freeware
Unix users are used to having a powerful, fast file-search utility, but windows users are starved in this area. Windows Grep is simply a windows equivalent for its unix namesake. It works nicely; it has a good interface; it's fast, and it has a nice replace feature. File searching is often overlooked in windows, because the operating system doesn't come with a nice utility for doing it. I shall omit the very tempting rant. Just get Windows Grep.
Shareware USD 30.00
Icon Editor (what did you think?).
Does everything you'd expect. Does it nicely. Handles your icons in convenient libraries. Buy it if you do icons.
Shareware USD 34.95