This was also a tough one. While my favorite color is blue, as a kid, I always chose green, because those that had green lightsabers were usually the most powerful (and ROTJ is my favorite SW movie).
That was until season 2, episode 10 of “Rebels” when Ahsoka ignited her double white lightsabers. When I saw them for the first time I almost lost my sh!t. They were the coolest sabers since the Darksaber.