This question came up in conversation earlier today between a friend and I. Basically, we never came to a definitive conclusion but we did concur that Lee's physique was not as good as Arnold's in that ceteris paribus, Arnold's muscle definition is almost on par with Lee's but his clearly superior size gives him the nod.
However, we also agree that part of what makes a good physique is what it is capable of, and in that respect Lee far overshadows Arnold, without even taking into account his mastery of martial arts. We agreed that the one-inch punch, the one-arm, two-finger pushups, the 30 minute "dragon flags" and the ability to make a 300lb punching bag hit the ceiling with one side kick all are more impressive physical feats than say, benching 450lbs for 8 reps or whatever the hell it is Arnold was moving in his prime.
So I extend the debate to the T-Nation crowd. Who do you think has the better physique and why? Obviously, if you're a pure functionality guy then Lee has the superior physique and if you're an overall size type of guy then Arnold is your man. If it comes down strictly to aesthetic appeal and symmetry then it's a toss-up.