In reply to idiotproof (Buxton MC):
Episodes I, II, III, IV, V then VI. Because then it should start crap, get better, get really great and then you kind of have to excuse some weaknesses right at the end with VI.
Or, you could just watch IV, V, VI and forget about the rest, you won't be missing out on anything really.
With all the disney ones, I don't think it matters all that much, perhaps in the order they were released.