Well my greatest dream would be to become god. LOL
Not like I would like to be worshiped but I would like absolute independence and power without any responsibility. It cant be completely achieved but you can move towards that goal.

Considering guro scenario there is no single perfect one. I like big variety guro and non guro stuff, but in general I prefer happy extreme unrealistic stuff which is more like extension of what I wrote above.

for example one scenario a relationship with tomboy girl who is immortal like Mai-chan, we get into some fighting like brother and sister and play games of torture.