Hi everybody,
I'm really happy that everybody so much enjoy this debate. Beside a week in London and a week in south of Spain, I havn't been to Europe, so I hardly saw in my own eyes real castles (only on books and movies). I'm a history freak and I now history pretty well though I never studied history in academia, so I love to hear others view about the subject.
I was pretty sure that the rivalry will be between 6080, 6074 and 375/6075.
Obviously I was mistaken

a really close race I must add.
Now why I love 6080:
1. In my eyes this is how a real castle look like. I must add that when I were little I saw this anime series which according to what I remember, a castle exactly like that was there. Again I was very little and I couldn't find that series on the net and I'm probably mistaken. When I saw 6080 for the first time (at my friend place) I was shocked how realistic it was (again to that same castle on the anime series).
2. Was my first castle. With that castle my obsession to castles and LEGO castles began. I guess you had to be there...
3. A very big castle, 664 pieces, 12 minifigs and 4 horses. Included a lot of light gray bricks and 30 wall pieces. On 1984-1987 it was the biggest castle ever made, comparing to 6073/6074 that the Black Falcons had.
4. Her back rooks can rotate 180 degrees.
5. As others said it can combine with:
6061 - Siege Tower (a must have expansion set to combine to it)
6040 - Blacksmith Shop
6041 - Armor Shop
6067 - Guarded Inn
6081 - King's Mountain Fortress
and I guess it can be combined also with the BF castles 6073/6074
and also 6062 (the expansion set to 6074).
I guess most of those things you can say also on 6085 though for some reason the front of 6080 castle is more attractive (in my eyes) then 6085.
As for 6086, don't get me wrong, I llike that castle, it took me ages to get a hold of one, the 2 rooks are great, included nice army, I even like the rasied base plate, but something with the front gate of it doesn't look real to me, something with the red roof there and the tower on the gate (the same btw with 6085).
If I had to vote for the 2nd most real I'll probably go with 6074 or (and I know my head is about to beheaded when I'll say this) 6090 (although it's not fortified enough I guess). I still don't know why it's considered fiction (beside it's unrealistic lion symbol).
Long live History, Long live LEGO Castles... (just not ones that looks like 8781)
BTW: My ICQ number is available if anyone wants to chat.