I have been using BitDefender Internet Security 2017 for a few months (bought it in 2016). It has been getting good reviews in the PC mags for several years. So far it has worked fine. The only issue I have had with it is that you can't do a simple pause. Pausing it requires an involved process of turning each service off and is a real PITA.
I gave up on Norton years ago when it started slowing everything down a lot.
Dropped TrendMicro when they started insisting I uninstall the last version before I could install the new version and it took forever to do it. I also had trouble getting my wife's computer to be accepted (I had either a two or three computer licence)
Used Kepersky for a few years and was happy with it but dropped them because my wife swore it slowed her computer down so much when it was scanning that she couldn't use it. I did not have that issue but it was easier to get a new program rather than listen to her complain.:)