Kaspersky is widely regarded as having some of the most sophisticated detection technology in the industry.

Bitdefender is consistently ranked at the top of independent lab tests for malware detection.

Never install more than one "real-time" antivirus at once (e.g., Bitdefender and Avast together). They will fight over system resources and actually make you less secure.

If you use Windows, you already have this. It has evolved from a basic scanner into a top-tier security tool.

Avast offers a massive suite of features for a free product, including a network security scanner and a "Do Not Disturb" mode for gaming.

Excellent at catching "zero-day" (brand new) threats and fileless malware.