On my Mac and my PC I use Kaspersky ONE. I've found it to be the most secure and efficient Anti-Virus/Internet Security on the market. That is of course my opinion. I've just had extremely good results with it.
For my PC I use comodo. Very good but you do need a bit of savvy to use it fully. I also use Glary, Windows Defender and Spybot. Otherwise AVG. I would never touch Norton, too power hungry and most likely always will be.
Comodo firewall free, highly configurable, and Malwarebytes.
Trouble with firewalls and AV programs is the more popular they get, the more they have specific attacks written for them. Back in the day ZoneAlarm used to be top notch until everyone started using it, then it had a big red target painted on its back.
I would say this though, never have both your firewall and Antivirus from the same company, don't use "all round" security programs.