On my main PC I'm only using Windows Defender. Otherwise, every computer in my house has Kaspersky on it. I've used K for years, and as an IT pro I recommend it. I can't speak for any of the free anti-virus packages, as I don't use them and don't research them, but what I tell people is that they should watch for the rebates at Fry's and can often get Kaspersky free after rebate. Myself, since I'm running a server at home, I can't use a freebie or a consumer version, because they don't run on the server OS, but I use a small business approach and get Kaspersky for something like $200ish for either two or three years (I don't remember which I bought, but I won't be needing to think about it for a while) to cover up to 10 computers. That's less than $10 per computer per year, so not bad.
The reason I'm not using Kaspersky on my main PC is that back when I was still running Win8, Kaspersky conflicted with the Windows Phone Emulator, which I need for development. So I just uninstalled K, but knowing that I have a good level of confidence in Windows Defender. No anti-virus is perfect, but some are better than others. I haven't been infected in any of my computers (my wife and I together have six computers) for years, and I also install Kaspersky from my license on my step-daughter's computer, since I have extra licenses.
I am rabidly opposed to both Norton/Symantec and McAfee. Both of these are such a pain to deal with, and wrap their tentacles around so much of your PC that I tired of them probably about 7 years ago, I'd guess, which is when I started using Kaspersky. As an IT pro, I can't tell you how much I cannot stand either of those two products.