Ignoring free software, the commercial/shareware stuff I use most is:
Microdot-II
Wordworth
Turbocalc (actually got this off an Aminet CD, which I got free for uploading something..)
MakeCD (which is free now, but I paid for it)
Honourable mention to Pagestream, Photogenics and SoundFX, which I don't use very much but are invaluable when I do.
