I am a big fan of editplus, it loads up instantly. has the about the best approch for multidocument editing, with its tab strip. It's syntax highlighting is extensible, and there are syntax files for every launguage i've ever needed to code in. You can set up macros(like to run perl code in a cmd console, or compile and execute the current java file), preview HTML (and HTML templates).
In my opinion though, its best feature is the FTP menu, i never need to use another application for ftp when i use this, cause you can open and save to a list of FTP sites you define, automatically.
For some code however, i prefer gvim for windows, especially for large files with complex regexes, POD, here docs. Vim's syntax highlighting is second to none.
On unix i use gvim or vi.