The truth is that there is no 'best' antivirus app for Windows. Most antivirus apps - including Microsoft's own Microsoft Defender - are equally effective at what they do to protect your computer. The best app for you is the one that you like best, because you like the interface, or because you like the app's website, or because you like its technical support, or because you like the extra features that come with it.
Don't think that Microsoft Defender is 'best' just because it comes from Microsoft. While nobody knows Windows better than Microsoft, no one knows what an attacker will do any better than anyone else.
Regardless of which antivirus app you choose, it's important not to rely on an app exclusively for protection. Study after study proves that most successful attacks succeeded because they were able to fool the user. So yes, use an antivirus app, but it's more important to keep yourself informed so you don't get tricked.
Best of success to you.