I use Noto Sans, or the Liberation Sans / Liberation Serif fonts. Tend to have a mix but Noto Sans for most desktop/GUI fonts.

I also quite like Libre Caslon and EB Garamond as serif fonts for reading, so tend to use those with e-reader software or on my ereader device.

I do install the old Microsoft Fonts just in case/out of habit but they seem to be disappearing from the internet fast now.