Me, personally, I use McAfee 8.5, the one my school gives students for free through a download on the main site, and it works fine for me. Some computer geeks are obsessed with having every nook and cranny covered, but as long as you don't do stupid shit, like download everything you see from untrusted sites, you can just stick with a good-not-great virus scanner. Your computer should have come with one, maybe as a trial, but if that one works, just go ahead and stick with that. But I use McAfee and it's caught alot of the threats and stopped them. That's for antivirus, for spyware and adware, I use Lavasoft's Ad-Aware which was also free for me for some reason, and that weeds out unnecessary files.