This is what matters to most to me and why it will rank high on my list, but there are already a couple shows I would put ahead of it and I'm not too impressed with what is coming in the fall.... (sorry, Eupho just isn't high on my list...) I still have to take a close look at everything coming out, but yeah, it will be tough to know out of my top 3-5 this year.
entertainment value is the top thing for me.
rewatchablity plays a factor too.
My top anime tend to be shows that when I watched I was excited for the next episode, and that I would be more than happy to watch again.
stuff like animation doesn't have much effect on me in terms of making me like a show more, but poor animation can make me like a show less. (basically as long as it hits oh... current one piece levels of animation it doesn't have much of an effect on me)