Samsung Galaxy S4
Same goes for the Samsung Galaxy S4. It remains one of the best options at T-Mobile, however, it will be replaced in early 2014 by a new Samsung Galaxy S5. Until then though, it remains one of the best options on T-Mobile's network.
Like the HTC One, it comes with solid hardware but maybe more important, it comes with solid software and software support. Samsung typically keeps its devices updated for two years or so, meaning, this phone is going to see several updates next year.