Choice of editors seems to be a very personal matter, so this is just my little point of view.

Under Unix I use Vi, it loads quickly which makes it ideal for small changes, and seems to be available on virtually every machine and able to run during quite severe problems. Whilst I don't do sysadmin professionally anymore (Yay! No more 2am call-outs) I did find it very useful then.

Now at work I develop on a Win2k desktop connected to Solaris servers, and I use Ultraedit. It's got a fairly nice collection of editing tools, syntax highlighting (Including Perl) which you can create your own syntaxs for, Save/Load to FTP which saves me an awful lot of time, and as been said before it can be configured to run scripts and leave the results handy. Do find it useful to be able to add to the syntax highlighting, allowing me to do things like write my own highlighter for Macromedia Director's own language Lingo.

It's entirely possible other editors provide all this, but I thought I'd just let you know my own views on this powderkeg matter.