Kannagi could be a lot better, but it's fine so far. Index has strong points but seems to put the focus on its weaker elements. Toradora is funny, has one of the best male/female friendships I've seen recently, and features a Kugimiya Rie girl I don't want to punch in the cunt, so A++ material there.
Haven't seen the other two, nor have I heard much buzz about them yet.