Whee, Dark Souls. I've played Demon's Souls and Dark Souls.

Really enjoyed Demon's Souls. And Dark Souls is nice, but it pissed me off a lot. It was trying so hard to kill me that some parts stopped being fun. (Damn archers on the roofs of Anor Londo!) But I still liked it. They aren't too difficulty--just initially punishing. If you can learn to dodge it's fine. I'm not a terribly great gamer (but a persistent one), but I did manage to platinum both.

I have Dark Souls II, but I just can't get into it. I played Bloodborne before it, so when I got to it, it felt like I was moving and performing actions at a turtle's pace. Just couldn't take it.

Speaking of Bloodborne, though. Love that game so much!