imo, aesthetic RGB is fine; I have a Hue+ in my personal build, and it's amazing to be able to choose any colour or effect for my PC if I ever feel like switching up my colour scheme.
RGB on graphics cards is fine, as long as it's tasteful (imo, the Strix cards do this well).
anything else is pretty unnecessary, save the Asus Rampage Extreme VI, because that just looks incredible.