You can take a good, proper snapshot of your viewport using "Viewport Render Image"
Alternatively, you can add a wireframe modifier, with the thickness set rather low, and uncheck "replace original". You must also set the "Material Offset" to 1. Then, give your mesh 2 different materials - one to represent the wireframe, and another for the base mesh. This is what it looks like in rendered preview - it can then be rendered as normal:
The last option, if you have lots of objects, and don't want to have to manually add a wireframe modifier and materials to each of them, is to use the cavity overlay. This doesn't have as strong a wireframe effect as the modifier, but it is still visible. You may or may not want to strengthen the effect with a matcap.
This effect looks best in solid preview mode (not rendered), so if you're going this route, capture the image with the viewport render option I listed above.