Windows: Popular adware removal tool Ad-Aware just keeps on improving, adding Outlook email scanning and live download verification, and a (regrettably tiered by price) rootkit removal system to its standard suite of scans and sweeps for bad stuff.
If you keep Outlook open during your working day, Ad-Aware 8.2 can monitor emails as they roll into your inbox, catching bad attachments and ad/mal/spy-ware laden links. Its "Ad-Watch Live" feature gets a few improvements, too, but the other notable news is a rootkit removal tool. The removal tool is tiered, so its ability to dig in and win back your computer's security improves as you pay more for a higher-priced licence, but the scanning and detection facility is common to all versions, thankfully, so at least you'll know what you're paying for.
Ad-Aware 8.2 is available as a free download for Windows systems, along with Plus and Pro licenses for $US27 and $US40, respectively.