Nexus S is a good choice.
Atrix is a great choice if you're willing to tinker with it. Motoblur sucks, but that is remedied with a custom ROM. Motorola released like 100 phones last year, 20% of those are probably worthwhile if you can get them sub-$300.
Huawei has some really nice looking phones, my favourites in terms of appearance. I think only the Glory will be on par with the current crop of superphones. The Honor is similar to the Nexus S spec-wise, and they probably have a few others too.
If you can find any GSM version of a phone from the Galaxy line that's in your price range, it's a worthy buy.