Articles
This talk by Mariko Kosaka called How to be a Compiler both for its content and format.
The Mathematician's Lament is, I think, essential reading. It begins with a description of a musician's nightmare where music is taught in the way math is today.  
Steven Heidel's Practical Functional Programming provides great examples of the thinking behind functional practices. 

Artists
The futuristic, digital landscapes of Simon Stålenhag
Chuck Close's portraits
I met Charles Ritchie a few years ago. More recently, Sophia and I went to visit him at the National Gallery in DC. He's an amazingly nice man and I can't get enough of his work. I have spent hours on his website. 

Audio
This episode, "Numbers Stations", of 99 Percent Invisible is a rebroadcast of David Goren's piece Atencion! Seis Siete Tres Siete Cero: The Mystery of the Shortwave Numbers Stations.

Poems
Frank O'Hara: Mayakovsky, My Heart, and To the Harbormaster.
Gerard Manley Hopkins: Pied Beauty

Projects
Bjørn Karmann's Objectifier is a useful example of machine learning.

Programming
I do most of my work in VS Code.
Recently, I've begun using the Python extension Bokeh to plot data. It allows for some great, interactive plots that can be helpful when looking at large sets of data. 

Videos
The Scared is Scared is the source of many quotes my fiancée and I use as inside jokes. It's incredibly clever filmmaking and endlessly charming.
Where Do Ideas Come From? puts forth many hypotheses as answers to the question - some contradictory - as a way of exploring a space in the mind as mysterious as the moment we drop off to sleep. 
This interview with Linus Torvalds

Websites
kottke.org is a wellspring of hypertext products dating back to 1998. 
ubu.com is a repository of the weird and avant-garde.
There is a load of material on philosophy in the Stanford Encyclopedia of Philosophy.
Scientific and mathematical papers on Cornell's arXiv.org (the X is the greek letter Chi so the website is called "archive").

YouTube Channels
3Blue1Brown makes amazing visual displays and explanations of math concepts.
Enjoy some practical applications of the scientific method with CaptainDisillusion.
ColdFusion has interesting and in-depth ideas about the interaction of technology and society.
Bill the engineerguy will introduce new ways of looking at the common products around you. 
Essential Craftsman is currently documenting the construction of a house for the purpose of education. 
I have watched hours of film and social analysis by Every Frame a Painting, Folding Ideas, Hepyrian, Jack's Movie Reviews, kaptainkristian, Lessons from the Screenplay, Musica Universalis, Now You See It, Pop Culture Detective, The Royal Ocean Film Society,  Viewfinder, Will Schoder, and YourMovieSucksDOTorg.