Hunter x Hunter: Figured I'd give this a shot despite never having watched the first run. I actually had the second episode ready for watching before deciding that I could find better things to be doing. I realize that this is a remake of a classic, but at this point it seems pretty campy.
Chihayafuru: I was going to give this a shot despite the questionable premise, but realized about 2 minutes in that this was either Shoujo or Josei, paused the video to look it up, and then nuked it from orbit. NEVER AGAIN. No, seriously, I've tried to watch/read female targeted anime/manga several times before and have yet to find one where I didn't want to violently murder the entire cast sit the cast down and tell them that most of their problems could be solved by proper communication and/or not being an idiot.
Horizon: I watched two episodes (as it is my policy to give most shows at least a second chance assuming the first episode was watchable), and this is terrible. The writing is just bad. The exposition goes beyond bluntly awkward, and worse, the whole presentation is just pretentious (throwing 50 generic terms at the viewer in the first half of an episode without ever explaining them is just shameful). Add to that a "hero" that seems to be suffering from brain damage and you have a show that's a lot of work to follow with unlikely payoff.
Fate/Zero: While there are some issues with terminology drops kinda like Horizon, this handles them much better overall. While I will need to watch the whole series to be sure, thus far it seems to be better than the first Fate anime as I suspected it might. I especially like how they are being somewhat reserved with how the violence is depicted (happening in dark areas and/or just off-screen, etc.), which has far more impact than if they had embraced their guro fetish and had to censor everything (*cough* Blood-C *cough).
Maken-Ki: The pacing for the first episode was pretty terrible (and let's face it, the story is kind of a generic harem action story), but I'll give it a second chance. Humorously, my biggest complaint for the show thus far is that the voice casting seems wrong; I can usually turn off my brain to get some enjoyment from these shows, but when the voices seem so... wrong... it's harder to do.
Mashiro-Iro Symphony: This is just... wow. I'm sticking to my policy and watching the second episode, but I have no expectations for this. The writing isn't great, and the pacing of the first episode is just atrocious.
Tamayura: I actually really like this one so far. The first episode was really slow, but this is the sort of show where going slow is desirable (and being slow doesn't automatically mean bad pacing, either). The problem with stories like these are that they often become unbearable if one of the main characters takes a sharp left turn into stupidville or they start to tackle "serious issues" halfheartedly. I have high expectations, though.
Phi Brain: I watched the first two episodes, and I'm probably passing on this one. This show suffers from an acute case of taking itself way too seriously, which is unfortunate since the premise is something that could easily be used to parody these sorts of shows. I have admit that the OP is stupidly catchy, though. Incidentally, I can't look at the heroine without thinking of the Muppets.
Haganai: I've tried to read the manga twice and never made it very far in, but the anime is a little easier to watch. I doubt I'm going to give this my "best anime of the season" award, but it seems watchable enough.
Majikoi: I really wish this started more at the beginning, but I can actually see how starting where they did might be preferable. Assuming that they go back and properly explain how they got to where they are, this is forgivable. Beyond that, I rarely complain about action-comedies (even harem ones) unless they get stale or especially stupid.
Mirai Nikki: I'm not watching this. Looking back, the manga was tiring to read with all the gratuitous violence, mind screws, and general prioritizing of style over substance. Yanderes aren't really my thing to begin with, and that's about all this has going for it.
C3: I'll give this at least a couple more episodes. I'm not sure yet if this is more Kore wa Zombie Desu ka (which I really enjoyed) or Hidan no Aria (which was more a guilty pleasure) yet. Thus far the action seems decent enough, but the comedy is hit or miss.
Ben-To: I'm not sure what to make of this. At all. It's definitely winner of the "what did I just watch" award of the season.