For a few years now, I've really dug serif'd fonts, even when wanting a monospace experience. My previous combination was go mono and charter -- I've got a shot of those here with the base16-grayscale-light colorscheme.

About 6 months ago, I pulled the trigger on some commercial fonts by Matthew Butterick, and now my combination is Triplicate and Equity. I'm recently trying out a soft looking emacs theme someone made by playing around in the lab colorspace. Here's a shot.