The Lotus was my favorite being my first. Second, I have always fancied the indoor Arena stage from the 81 tour. It's similar to the Lotus stage ,very open but with the drums and equipment section able to rotate from one side to the other. The televised show from Hampton VA they added runways on both sides of stage that ran almost the whole length of the arena very cool.
My favorite is the cobra stage. The lotus stage wasn't used for outdoor shows in '75, so we made do with a predominately peamockly (my dad's word to describe that particular hue) green stage (and band outfits for that matter) at Milwaukee's County Stadium.