Misty Mountain. (& preferably not the popular dwarven chant "Gold")
Of course much of this backstory is actually told later in the book, long after the poem - but in a movie it's surely better off upfront with the credits rolling after the fire hits the screen in full tacky 3D. (Of course I never envisioned that - I mean back in the day 3D was the tackiest, I think my young self would have had an appoplexy ;) Possibly, though, with the fact that the Hobbit will actually be two movies, maybe they'll leave Smaug's devastation until part two. I guess so long as that Dale burns, the river turns to golden fire and Smaug looks like he belongs up in the air, dangerous, terrifying and almost elemental - then I'll be happy.
In fact talking about it, I realise some of the details of my little movie are blurring - what a shame, I'll just have to read the book again before I watch the movie. It's been a long time since my children were seven and "The Hobbit" was the bed-time book of choice, and we were quoting vast chunks of "here am I, naughty little fly..." Now the bed time reading is serious alone time featuring things like George RR Martin and Brandon Sanderson, and other such unwieldy epics (ignoring the cute little cat books and the devastatingly off-putting reading logs). So it will be sweet to get back to my favourite book of all time.
I am so looking forward to the movie. The LOTR people may bee playing with my
favourite book for over thirty years... but they played LOTR pretty well, and even when I thought their choices were wrong it was still obvious that Tolkien's books had been treated with
love and respect. So bring on the movie. And bring on the dragon, enter top right screen, turn toward us up the river and let those flames erupt!
And don't forget to read Over the Misty Mountains, it has to be amongst Tolkein's best poems, not that I'm biased or anything. But the rhythm is compelling. I also feel compelled to add just the end of the shorter little ditty that Bilbo's cheekily sings to the spiders of Mirkwood...and I'm probably paraphrasing here and getting it wrong anyway..."here am I naughty little fly, you are fat and lazy, you cannot catch me though you try, in your cobwebs crazy." It's so perfectly catchy for young uns.
FYI. The book cover shown is the same copy I read to my children when they were smaller, illustrated by Alan Lee it is quite charming and has survived a lot of reading!