Late last week Microsoft released a new version of EMET. I’ve written about EMET before and I still recommend it. EMET 5.0 adds a couple of new mitigations, tries to be harder to bypass, and offers improved compatibility, so there’s little reason not to upgrade.
EMET does more than anything else I can think of to protect you from the many things that get past your antivirus software and firewall’s defenses, and it’s free. I can’t think of any good reason not to run it. Of course, the people not running it at all stand to benefit the most from it, but if you’re already running EMET 4.1, upgrading to get better protection is worthwhile, too.