Get a Mac
I have had my Mac Mini and MBA for 2 years now and have never installed any anti anything on them and both are clean to this day. Though I do expect this will be changing in the very near future. I do not use Find My Mac (Any access to my Apple ID could erase my machines - See
THIS)
On my one remaining PC I use AVG (Free Version) and nothing else.
McAfee and Norton always seemed to have issues in some way shape or form. I did like Webroot and used it for a while. I just do not use my PC enough anymore to invest a ton of money in anti- software.
Most importantly all my files are stored off my computer on separate hard drives. They are backed up to a second hard drive and to a cloud based backup service. 2 is 1, 1 is none, and 3 is better.