We had Mike's Roofing do ours.
http://www.mikesroofinginc.net/
The scheduling was a bit of a pain and it took longer than I wanted. We also needed them to come out 3 or so times to make tweaks.
But, they did come out without a hassle and once the last of the tweaks were done we haven't had any problems.
I've had other contractors remark on the good quality of the work.
So, overall, I think they're a good choice.
My suggestion though is that you join the Home Owners Club and work through them. They're a referral service and so you get extra leverage that you can use to protect yourself.
http://www.homeownersclub.org/
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