To me, the question "
Who will be left after all the dust settles?" implies that the remaining companies will have the reputation, knowledge, dedication, and financial capacity to last seemingly indefinitely (under the best circumstances of course).
With that in mind, I'd say my primary pick is ASICMiner, solely based on how far they've come already...and assuming they continue to develop chips that outpace competitors.
Choosing a second company is difficult though. I'm not sure any of the other options truly fit the bill, but KnC, CoinTerra, Bitmain, and BitFury are close.
And then there's BFL, a Bitcoin-parasite who will be around so long as their lawyers don't leave any loopholes for them to be sued by, all while slowly draining the wallets of any newbie who can't use a 'search' function.
![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif)