I don't know..Southfork is just so iconic for me, and I've been there... 26 years ago next month.
For me, though, I'm going to have to go with the Falcon Crest mansion. I love both the interior(we see on the show), and the exterior. Have no idea how close it is to the real interior(probably not very) but then, I would have to say it's got to be closer to matching the interior than the Southfork set.
Don't get me wrong, I absolutely was thrilled to be at Southfork back in 2000, but realizing they shot every interior shot of the house elsewhere was a bit of a letdown(except one scene in "War Of The Ewings"). I loved the land surrounding Southfork, but I honestly would have also loved to be able to see the interior of the house they actually filmed interiors in for those early season 2 episodes. Terrible with names, and now memory..lol..but I'm thinking the interiors for Southfork were done at a mansion in the Little Turtle?? area of Dallas.
The Falcon Crest mansion. I've never made my way all the way to California. Actually, on the same trip my family took to see Southfork, we ended up making it all the way out to Vegas, but not California. On the bucket-list, I guess. It looks as though I would probably love the land surrounding Villa Miravalle, even more than I did Southfork, but it feels like we saw more of the land surrounding Southfork than we did the land surrounding Villa Miravalle on Falcon Crest. It may just be that I've watched more of Dallas, so it's just more iconic for me. I don't know.
The Dynasty house looks very spacious, and grand, but I was never as into that show as Dallas and Falcon Crest, and the Victorian mansion is good enough(lol) for this old man.