As far as you don't indulge into unsafe browsing and keep away from USB drives, Windows defender is ok.
Any further, you should have a better real-time scanner.
And as mentioned by
@TheMalwareMaster go for Zemana for on-demand. Much better than MalwareBytes.
Have uBlockOrigins, Bitdefender QuickScan, HTTPS everywhere and Bitdefender TrafficLight as addons for Chrome.
EDIT: Avira Browser Safety isn't supported in FF.
Be safe