I don't have just one favourite from 'A Thousand Suns'. My faves are:
Burning in the Skies (because I'm trying to get past things I regret from my long ago past),
When They Come For Me (because it's a brilliant rhyme, I reckon, and very meaningful about him), Robot Boy (because I know someone like this and it feels like I'm singing it to them when I sing along), Waiting for the End (because it's true that some songs have great feel and rhythm but seem really empty, lyrically, and because I sometimes want to trade this life for something new, wanting a life that I haven't got and may never get, and because sometimes my mouth keeps moving and my mind goes dead and I have to deal with the fallout - not pretty! :( ), Blackout (because a major person in my life has always been a taker, never stopping, but also comes from a difficult past and I feel that if they'd face their past and stop throwing all their feelings about it at people who are nothing to do with it, it would make their and the people around them's lives much easier and nicer and better), Iridescent (because I need to let go of all my failures and all the sadness and frustration so I can move on into a better future), The Catalyst (because sometimes we think we're doing right but we're not - good to acknowledge it so things can change), The Messenger (nice to know that Chester believes this too, and wanted to share it with us - nice-hearted bloke :) I was 'growing desperate from the fight', so it came at a good time for me).
Good wishes to you all,