For looks it depends upon the height of the tank, but when I had my 60 cube, 2' high, I had a high stand, 34", and the viewing was really nice, and with it being high, you got the full view of the tank.
That being say I think you need to take into considering a couple of things on the stand height, the first being the amount of room under the tank, as you want to have good access and you need to take into account the height of the skimmer. The second thing is if the tank is high, say 36", you need to take into account the access to it from above, so you may need a ladder or step stool to access it.