I don't always run anti-virus software, because I agree with Kaiserguard that common sense is the best way to avoid viruses, but when I do, I run MSE. It's relatively lightweight, doesn't have very many false positives, and when there is a false positive, it's easy to tell it to ignore that result. Although Malwarebytes is a good secondary option if you know something is up but your primary (whether MSE or otherwise) isn't detecting it.
I'd personally be disinclined to use McAfee. In my experience (which consists of using it on computers provided by employers), it tends to have a considerable negative performance impact, and I've heard similar from others who've used it. And even John McAfee himself recommends uninstalling it. He is a bit out in left field, but it's nonetheless bad when the founder of the company himself recommends against using its software, particularly since he isn't even running a competing company. And, with several decent free options, I'd be hard-pressed to recommend a paid option, even ones with good reputations like Kaspersky.
