Samsung is a last year model and completely lacks 1:1 pixel mapping, Sony has cloud/backlit problems, Aquos plagued with banding, the first four units of Olevia's new top 74x-series (with built-in HQV Realta scaler) has egg and bleeding problems - you pick your best. Rest of the crowd knows only less than these models.
Wait until Samsung's new ones start shipping although that scaler in the Olevia 74x models sounds really good (see other thread).