For me, it would come down to the C50 or the Look. While BMCs are interesting, I don't think they're in the same class as the other two. Purely unsubstantiated bias, but that's the way it is. I used to think the BMC was a cool looking bike, but my taste evolved. In terms of the $1000, in the >$2000 frame world, no bike is worth $1000 more than another.

Between the Look and the Colnago, might be a toss-up depending on which geometry suits you. Colnagos are slack in the HTA and the steering is slow(er) compared to the more traditional 73HTA of the Look (assuming the 595 follows the geo of the 585). If you're going to be riding crits, it might not be the best choice. The sizing on the Colnagos is also different in terms of setback and TTL, so make sure you end up with the correct size.

I've not ridden a 595, or any equivalent Look so I won't comment other than to say that the top end Looks have always been on my acquisition list. The pricing though challenges my frugal side. I do own a C50 and it's a darn nice bike, one that would satisfy just about anyone. Fit, finish and ride are all outstanding. In terms of geometry, Colnagos work well for me and because of that, I own 3.

As just about everyone else has said, any of these will end up being a great bike for you. Given that, pick the paint job that works for you.