It depends. I have a Kindle which is my main reader, and an iPad which I sometimes read on but which I bought for primary purposes other than reading. I also have an iPod Touch which is capable of reading, but I never read on it and use it for other purposes (in fact, if I did not have a need to display things to my students and hence needed a screen they could see, the iPod Touch would have met my needs for school use to play MP3s). I also have a Libre which was an impulse buy because I wanted folders and I had the idea to pass the Libre on to my father. The Kindle has collections now so it has become redundant, and my stepmother did not listen to my advice and bought my dad a Kobo
So it is the redundant one and I need to get rid of it some day.
But really for me, it is 'Kindle, my proper reader' mostly. I don't really the i-stuff because I bought those primarily for other purposes.