Of those three I've only ever watched a few seasons of Six Feet Under - which did have a few great episodes.
The only one that really stands out in my memory is the one where David gets bashed by a methhead hijacker. That was without doubt one of the more chilling things I've ever seen on TV.
On the whole, I think there's a lack of different "psychological voices" in flagship cable, but we've had that argument about (among other things) the limited range of storylines out there before.
It's perhaps not so much the commercial imperatives, as that the relationship between what gets greenlit and what achieves commercial success is getting a bit too refined at the moment.
Preacher for example. For all its merits it's another property that can be adapted to the HBO/AMC pulp mold, because its story revolves around an outsider white man getting sexual and violent gratification. It's a trouble if you can already visualise the deliberately controversial missteps of the TV adaptation, and the blogs and the sanctimonious "longreads" in Salon and The Atlantic that will result.
