Bit Defender and malware bytes are among the best.
But I'm going to be honest with you, the free stuff isn't as good as the paid stuff. The paid versions contain more features which more actively protect your system. The free stuff may keep you from sketchy sites, avoid TLS 1.0, and catch most virus attacks, but lack advanced remediation routines.
Paid software contain advanced features like encryption lockers and protected files to protect against advanced system changes and ransomware. So if a new virus comes out, and the first level of defense fails, the paid versions have additional backups to protect you.
PS: Some "Free Versions" also might sell your personal behavior and email addresses. This is one revenue stream to keep "free" going. So read the terms of service CAREFULLY.
You know the saying "You get what you pay for."