I think DD and SG are quite distinct, as in the first the plot servers more than taking you to new areas and you really have to stick with it.
One of my favorite things about the Sacred games is that you can just wander around, killing things (BTW, I *like* the respawn factor), and getting to an ever higher level and grabbing ever better loot along the way. The plot is virtually nonexistent, and you only have to do it once you want to go one difficulty level higher. (On this note, Silver, Gold and Plat are only slightly different. Niobium, on the other hand... NOW we're talking.)
DD is great because of its atmosphere and the well thought-out chars. But, indeed, it needs patching.
So, the bottom line is: IMO, both are masterpieces in their own ways and are different enough to make comparing them to each other pointless.

I agree, both are unique and classic in their own way. I guess my point was not that they are the same but . . . if someone liked either game they would probably like the other game as well. They are both on my favorites list. . . .=^ )
Edit: I enjoyed the huge area of SG and wondered so much that often, when I went back to the main quest, I was almost too strong for the enemies . . . that was kinda nice though . . .=^ ) . . I also think DD has one of the best atmospheres of any RPG game that I've played. It's almost relaxing to play . . . if that 's the right word.