Some of my favorite expressions:
sin((x+y)/4+t)
: simple yet beautiful!sin(sin(t)*(x+y)/4)
: first real creationsin(t-sqrt(x*x+y*y))
: not mine, but wow!sin(y+sin(x+t))
: wavy flag, moves in -x directionsin(t-sqrt(x*x+y*y)+sin(sqrt(x*x+y*y)+t))
: awe-some!