No way I can pick a single painting. I love too many.
One of the big Dienbendorn Ocean Park Series paintings.
A late Philip Guston (Painting, Smoking, Eating?)
An Amy Sillman. One of the Howard Hodgkin paintings with really long active dates (some were started and finished 10+ years apart). A Thomas Nozkowski.
A geometric Mondrian. Not the most original but hey ho
When I was young we had a Modigliani portrait print that used to scare every kid who came to our house with eyes that followed you. That would be a nice one to have for sentimental reasons
Guston, when he created a stir and went figurative to the outrage of the art world, are some of the most powerful paintings ever in my opinion; and obviously now celebrated. Although, they are a bit too intense for me to want to wake up to across from my bed or to look at while eating but he and Hammershøi are easily my two favorite painters.