Foxit PhantomPDF offers a lot of features at a great price. For many, it will replace Acrobat...but you'll need that 30-day free trial to make sure it does exactly what you need.
Foxit Reader is free, it's lightweight, and historically it has been less problematic than Adobe Reader. If you're burned out on Adobe Reader, there's a lot to like.
Efficient Calendar pulls the best of Microsoft Outlook's calendar functions into a standalone app, but don't expect significant data portability.
DDownloads helps you download popular programs straight from the source. It's free, and for the programs on its list, it works well.
Multi-Process Killer makes ending multiple processes simultaneously a breeze. Knowing which processes to kill is the hard part.