I'm not sure. Personally as I said, I'm more biased towards the Inspire, as HTC phones just work. If I were making the choice, I would save the hundred bucks and get the Inspire. That would be my personal choice, but I'm not sure if that is best for you or what is in your heart, since a phone purchase can also be an emotional one.
I got a strong love-hate interest with my Samsung Galaxy S i9000 last year, but with all the refinements, all the late batch type Galaxy S type phones seems to be doing much better than my early piece. My own Samsung phone pissed me off quite a number of times, but after its Froyo upgrade, it became much smoother and reliable. Its been half a year now with my daughter's hands, and she's quite happy with it. So at this point I cannot make a summary judgement on Samsung's quality. Especially after my daughter's Galaxy Tab and my own Nexus S are also both doing that well.
Should note i've been using a lot of HTC phones, with my current ones a Droid Incredible and Desire Z, and I'm very happy with both, though happier on the Desire Z. Again, if that is representative, the Inspire would be a winner.