I really like the mathematical impressions from Fomenko

http://chronologia.org/en/math_impressions/images.html

For programmable graphics, I like Penrose https://www.cs.cmu.edu/~kmcrane/Projects/Penrose/Penrose_SIG...

And finally the same author as Penrose (Keenan Crane) has a challenge for creating beautiful visualisation of abstract and difficult math concepts, but at the moment I'm unable to find the link