I'm a mood reader as well, and pretty much agree with Athena - I usually have 2 books on the go, my bedtime book and a commuting book (which is usually an easier read, and also easier to carry, big books are saved for the bedside so I don't have to cart them around), but my choice does depend on my mood; sometimes I might fancy a particular genre, or if I've just read something a bit more serious then maybe a short, light read eg cosy crime or a favourite series, will be next. And yes sometimes I'm spoilt for choice too and can't decide, in which case an old favourite is usually fished out. I do have a tbr list on Library thing, but don't stick to it that much although I do try to read one from that list sometimes. My new year reading resolution was to read one old, one new, and it's working a bit, but I'm also trying to read new books fairly quickly as well. I don't like to have a set challenge as such, as reading is meant to be for pleasure so I don't want it to become something I'm worrying over, as there are more important things to fret over than what book I'm going to read next!