I played Dark Souls to the point in which the game became ridiculously easy to me. The game is challenging BUT it is also fair and in truth allows you to do a lot of cheesing. Once you know the enemy locations, boss attack patterns and the layout of the levels it becomes pretty easy. I love Dark Souls. Got it on 360 and got all achievements and then I bought the PC version. I got all achievements on the PC version but I also went and did a challenge run in which I beat the game at Soul Level 1. As in, never level up. Killed all bosses, including the optional ones from the DLC. **** was fun. It also wasn't that hard, honestly! The game REWARDS your KNOWLEDGE of the game. That's why it's so damn good.
Needless to say, I am REALLY looking forward to Dark Souls 2 and see how it will rekindle the flame of difficulty. There's a LOT of changes going on in Dark Souls 2 that make the game much better, from what I've seen, like how apparently low level characters can't wear top-end armors anymore (which was something extremely annoying in Dark Souls PvP). I just hope it's still a fair game.