Software wise, anything without a demo. The support from companies is dire at the best of times and if something doesn’t work on your system your screwed. In shops you can test the suitability of something by testing it (sitting on a couch, laying on a bed) but with software they take your money and run.
Also anything abandoned is fair game.
noli me cogere ut responde quaestiones inanes
Google translate made this for me years ago and I copy and paste everywhere