Gangrel's arc felt like it fit in with everything the best. It kicks off the plot, flows pretty well, and has a villain that you can really love to hate, but has a somewhat understandable (though not necessarily justified) reason for their actions. Walhart's arc felt too segregated from the 'main' plot, and the Grimleal arc felt too sudden and short. I felt like it would've been better if there was some more Grimleal activity mixed into the Valm arc (and the child paralogues, for that matter), and if we got to see the 'Hierophant' more than just a single time before his/her big reveal.
Ruler of the Unknown Universe "Courage is the magic that turns dreams into reality." - Emil, ToS:DotNW