Personally I do most of my editing in either vi(1) or emacs(1). Emacs has a few special modes for editing LaTeX files, but I've only used them slightly myself. They have cute features like automatically translating double quotes on input into two single quotes (pointing the right way even). I'm sure there are many more advanced features too, but I haven't explored them. If you're interested, you can find more information in the emacs manual.