I recently blogged about my favorite security applications, I neglected to mention one of the best antispyware apps available at any cost. Malwarebytes is available in free or paid versions from here http://www.malwarebytes.org/index.php
Malwarebytes is fast, lightweight, and very effective. I use it along with Superantispyware on all my machines as well as a antivirus application to keep me safe online.
Another new recommendation I can make is for Norton Antivirus 2009. Symantec started to greatly improve the performance of their antivirus product with their 2008 version. I was happy after using it for around 8 months of trouble free use, I felt it was vastly superior to the 2004 version I had last used. That said, Norton 2008 still slowed my computer down significantly when it would run a scan. Recently Symantec offered users of Antivirus 2008 a free upgrade to their Norton Antivirus 2009. After the download I was immediately impressed with the improved performance. The scans can either run at full speed or in the background using far fewer system resources, (and taking a lot longer). Either way there seems to be far less of a performance hit, a CPU meter displayed on the side of the display window shows how few resources the new Norton 2009 Antivirus uses.
While I do recommend Norton Antivirus, I still don't recommend the Norton Security suites. I recently tried a version of Norton Internet Security that came preinstalled on a new laptop I bought for my son. It suffered from all the bloat and connectivity issues security suites always do. So I commend Symantec for the new antivirus, but I'll pass on the bloated, all in one suites.