I got the Nook first (I liked the dual e-ink/LCD screen setup and the DRM scheme better). Then I got a ST upgrade and then a ST with glow (presents from the wife). Had a Nook Color running CM7 back when everyone else's tablets cost like $400...everyone would ask if it was an iPad.
Kids both had Nook Colors for about a year with CM7/CM10 also. Have a Nook HD+ right now and I don't even really know why, I use my Nexus 7 most of the time...I just like to play with it and its dual-boot setup.
Still prefer epub. I like to fix typos and such so Sigil is handy for editing epubs.
My wife has had a few Kindles though and I buy a Kindle book once in a while (then strip the DRM and put in my Calibre and on my Nook) .