I'm going to give my vote to HTC overall. I'm biased as I've stated in previous threads, all my devices through the years have been HTC built and I've never owned a pocket computer device built by any others. It just worked out that way.
But, looking at the other device makers, Samsung is doing far too much with Droid to give Windows serious consideration. HTC has a track record of producing really high quality Windows devices. Look at the Dell Axim x51v. the device was years ahead of ti's time at the time. They have the resources and technology still at hand to build outstanding devices that can blow the others out of the water.
Nokia, I just can't see them moving far if they continue to provide "exclusives". They are severely limiting their market and focusing on one, very small, market percentage. If they wanted to make the U.S. market something they can control, it would be by providing a device that works for every carrier out there. Then, with their "exclusive" apps, more people would be in THEIR market and want THEIR apps. That would increase THEIR profits.
I still just don't get the whole marketing debacle that has been Windows Phone from the beginning.