I like the four staffs, and how they weren't insanely powerful, they are strong but only for so long. Multiple map exclusive wunder weapons is where it's at, instead of making one insanely powerful, just make four that are decent/powerful.
Also, I love digging for items, I'm not sure why but when I see a mound of dirt I just have to dig it up. It doesn't have to be mounds of dirt, but some sort of a way to scavenge for items without the use of a perk.
I am also a big fan of out of map details. The planes fighting in the sky, the distant look of wartorn battlefields and of course, getting to watch the giants fade away as they walk out of map was awesome the first few weeks it was out. I actually get out of the map in theater mode sometimes just to go up into the clouds and it's silly to admit, but it's kinda scary going straight up into that cyclone of clouds, if that was in the game it would have been great.