Back in the days of Crash,Sly and medievil of course, but more recently I'd say C&C Red Alert 3 and these guys:
Giga fortresses were an Empire of the Rising Sun faction unit that had the ability to transform from a giant floating head that shoots laser beams from it's mouth to an actual floating fortress on water that can attack both ground, sea and air.
I always loved including them in my armies and watching them slowly hover over enemy bases or watching enemies appear from the fog of war only to be blown yo bits.
basically destruction and increasing levels of it in any RTS gets my favourite all time fun.

Giga fortresses were an Empire of the Rising Sun faction unit that had the ability to transform from a giant floating head that shoots laser beams from it's mouth to an actual floating fortress on water that can attack both ground, sea and air.
I always loved including them in my armies and watching them slowly hover over enemy bases or watching enemies appear from the fog of war only to be blown yo bits.
basically destruction and increasing levels of it in any RTS gets my favourite all time fun.