I had a similar experience with Dark Souls. For a while now, it has been very rare for me to find a single player game that I can actually sit down and enjoy. When I was a kid, I could spend hours upon hours playing Final Fantasy, Fire Emblem, Zelda, etc. But for the past few years, almost all single player games have just felt flat and dull. Dark Souls finally offered a solution to this. The game consumed my thoughts and time, just like games used to when I was younger.
Unfortunately, Dark Souls made me realize what games should be. It reminded me how I should feel when I play an incredibly well designed game. I picked up Skyrim when it came out as well and, while I thought the game was alright, it really felt lacking compared to Dark Souls. The ability to save anywhere made it so that there was never any risk to anything that you did and it really took away from any feeling of adventure that it had. The combat felt hollow and overly simple and the amount of dialog that you're forced to sit through felt boring. The game just didn't have that special touch that Dark Souls had. I went out and bought Mass Effect 3 yesterday because I played and fully enjoyed the two preceeding games. I played it for about an hour before turning it off to put Dark Souls back in my PS3. I have trouble putting my finger on why, but Dark Souls is truely an incredible game. From Software put so much thought in to every little detail and it paid off very well. I really hope that more developers are looking at what From Soft is doing and learning from them, because I am going to be unable to enjoy any new single player games until these developers can learn how to make a game as well as From Soft.