I just live with Windows Defender (heavily modified via GPO to disable sample submission and auto-remediation) these days as there is no such thing as a pure third-party antivirus product anymore. Avast (and basically all others) want to do things like install their own "safe" browser, MITM https connections by installing certificates in the root CA store, screw with firewall settings, etc which I absolutely do not want happening on my system.

All I really need is something that will hook into the filesystem layer and scan files as they are accessed/written/executed and gives me a clear UI that allows me to choose what happens if it detects something.