I have the Nook first generation, the kindle four (silver,) and the original kindle fire. I use all of them on a rotating basis; it all depends on what I'm in the mood for. I'm also getting another ereader for Christmas - the Kindle Paperwhite.
I once owned the Kindle Touch, but sold it to buy the Kindle 4. I bought the Kobo first gen as well, (after my Nook Glowlight's screen died on me,) but found it slow and buggy and sold it. I've also owned several kindle keyboards.
I think I'm an ereader addict.