The things I personally am over don't really have to do with fashion, over saturation, retail choices, or what other people wear. My short list is more like things I've worn for years that I've come to realize don't suit me very well! E.g. stripes and plaid, very classic or even preppie looks, boyish or masculine shapes and details.
Actually, maybe some of this is to do with what's in fashion. I kind of want the trend of wearing fashion sneakers with anything to go away -- but this is selfish of me, because I am jealous that other people wear it so well and it just looks weird on me!