In code I originate myself, 80 columns (though I allow myself the occasional insanely long line if breaking it up would somehow manage to be even uglier). I like to fill a high-resolution display with lots of 80-column-wide terminals and editors rather than maximising one window over the whole thing, and even if I didn't do that I'd like to think I'd have some sympathy for other people reading my code who did.

At work, I maintain (among other things) a program which was written by somebody with a wider editor window than that, and so far it has seemed easier to expand my own editor window than to do a big reformatting checkin. (Particularly given that his code wouldn't be very easy to reformat to 80 columns, since he did tend to draw all his identifiers from a naming scheme of which your last option is only a mild exaggeration.)