I just bought BitDefender Total Protection for a year. Here in my country. The official distributor sell it for about 13usd . For that price I got a year with 5 devices active at the same time. I used it for my Mac , windows, and android . 2 more for my family
On avtest website the review is quite good and well it's a no brainer for the price. Yeah, Mac has its built in Anti Malware etc but having redundancy is nice and knowing that if it's already in the BitDefender database before Apple's I can be sure that it Will catch it.
The last thing I like with having a third party av is that it detects windows viruses too. So if I plug in my family's USB, and it contains windows viruses it can clean it so that when they use it on their other computers. It won't be affected.