I loved Dark Souls, sadly the majority (seemingly) of the community surrounding the game are "tough" guys who play HARD games for MEN.
You shouldn't need to look up a walkthrough. Part of the appeal of Dark Souls is the breadth of the game, it's absolutely filled with secrets, it does have an old world charm to it. It's set up very much like a traditional Metroidvania, there's a great sense of mystery that would be ruined if you were to search walkthroughs. The game really teaches you to learn from your mistakes, observe, so being patience with the game is paramount.
Speaking only of the mechanics, the combat is engrossing, I've play few games with such tight mechanics, there's visceral feel to it, every little movement counts. Every victory feels like you've earned it.
But what I liked most about the game was the sense of atmosphere. It throws you into a seamless world that feels alive. The game doesn't hand you anything, even the events of the plot are buried. It's a grim experience that few games can replicate. There's a genuine sense of ambience, it really is the kind of game that engulfs the player. Though the press and such put an emphasis on the difficulty, there's much more to it, it's a shame really.
The game is an experience, albeit an unrelenting one.
Edit: Also, there's a lot of mention that the "story" or plot is weak. I'd have to disagree, you just need to look in certain places to learn more. It's actually rather clever in places.