There are 3 pieces of shareware that I've been using for a long time and like very much. They are:

Clipmate by Thornsoft Development - a little app that lives in the system tray and keeps the history of everything that is copied and pasted. It also lets you keep organized collections of "copies" and allows you to paste them in rapid succession. It can also do encryption, spell checking and other things as well.

Trillian by Cerulean Studios - everybody's favorite instant messaging client

Powermarks by Kaylon Technologies - a very, very, very good bookmark manager.

I am also using Snippets by SoftCircuits, but I am looking to replace it with some other hierarchical database. It has been at version 1.51 for many years, there is no development planned and it doesn't have many of the features that I need.

All of these programs a worth the money that I paid many times over. I wish I bought them earlier.

Right now I am shopping for a hierarchical storage database / outliner (something like Mybase or Treepad, but I can't decide because there are so many choices). I am also looking for an anti-spam tool (on big requirement is being able to look through my mail client and clean out the stuff that is already there, not only the new stuff that is arriving), a popup and ad killer (something like the now defunct Popup Killer, ) and probably a personal firewall in addition to the one in my router.

The common problems with shareware products are :
a) Priced too high (over $30) like Lyris Mailshield
b) The evaluation version is severely disabled like Axon Idea Processor
c) Given away for too small a fee or altogether for free, causing the development to stop like the Popup Killer which I mentioned already or even more so, like Semagic Livejournal client.

Which shareware programs do you like? Any recommendations?