Saying something brief about Black ★ Rock Shooter
Black ★ Rock Shooter (and that's the last time I am adding the ★ character to its title) is technically part of the winter 2012 season; it just started a month or so after everything else.
I thought that the Black Rock Shooter OVA had decently nice action but was otherwise mostly incomprehensible. The first episode of the TV series reduces the action and makes it less comprehensible (and more random) while swapping out everything else for relatively pedestrian drama (admittedly with a crazy person or two). In light of my trimming this season I've so far seen no reason to watch any more of it. If it had kept the quality of action of the OVA I would have watched it for the action alone, but it didn't.
(This is the sort of thing that almost fits in a Tweet, but not quite.)