[Sans]

If you are not using a multi-layered approach you are asking for it. Period.
There is no single AV utility that will protect you from a real attacker in a real attack situation. There just isn't.
BitDefender, MBAM, ESET Nod32 and Qihoo 360 all work amazingly well, but without additional layers they are not a complete security solution and should not be treated as one.

Microsoft's EMET utility, Malwarebytes' Anti-Exploit, Zemana's Antilogger, and rootkit detection utilities like GMER, MBAR etc. are ESSENTIAL for a safe Windows machine. A real firewall (hardware!!!) and a file integrity monitor isn't a bad idea either. There are amazingly sophisticated attacks and attackers out there, and if you're unlucky enough to encounter one, your antivirus will not save you. This is fact. Reality is cold and unforgiving. Face it now, or let it kill you later.

Knowing how your OS works often helps, too. Not to mention that annoying pesky Secure Boot feature that people disable because they wanna run a *nix OS or crack their Windows... That needs to stay ON. Learn how to sign your own bootloader, OS kernel and modules. Learn how to use the security features built into your system rather than turning them off. (and on that note, 'setenforce 0' should be a crime...)

Windows UAC (and *nix-based systems' sudo and RBAC/MAC) are a godsend. Disable them and you'll find yourself having a lot of "fun" very quickly in a real attack scenario.