Given that it's based on Homer, the story itself will always be pretty indestructable. Given that it's set in the deep south in the 1930s, the atmosphere is going to be compelling. Given the focus on bluegrass music, it's going to be near the top of my list. But when you add in the humour, the character development and even being banished from Woolworth's, you know it's top ten material.
As usual, good quotes abound:
Washington: Mrs Hogwallup up an' R-U-N-N-O-F-T.
Tommy: I had to be up at that there crossroads last midnight, to sell my soul to the devil.
Everett: Well, ain't it a small world, spiritually speaking. Pete and Delmar just been baptized and saved. I guess I'm the only one that remains unaffiliated.
Delmar [cheerily, after thinking about Pete being 84 when he gets out of jail]: Well, I'll only be 82!
Pete [whispering]: Do - not - seek - the - treasure.
Delmar [whispering]: We - thought - you - wuz - a - toad!
Add to that the legend of the Soggy Bottom Boys that grows through the movie - one of the best scenes has to be the look of surprise on their faces when they start playing 'Man Of Constant Sorrow' at the concert towards the end and the entire audience screams like it's a 1963 Beatles concert.
The whole thing bears watching over and over, beginning to end, with little references both to the period its set (yes, the KKK, but also children tied together with rope was, I am told, a common practice to keep track of them) and to the Greek original (Sirens, Cyclops etc). Brilliant story, beautifully filmed, gloriously acted and with a soundtrack to augment the whole thing.
A thing of joy. Well done everyone concerned.