I don't know all the paintings that are in the game (I'm trying to avoid getting any help when it comes to telling fake paintings from real ones), but one of Frida Kahlo's self portraits would be nice, to give to Hazel if I had her in my town.
Something by Dali. It surprises me that there's something by Gaudi in the game but not Dali. Also something by David Hockney, simply because I live near where he's from.