I'm not sure what the u1 is, but I'd say the g15 from that list. However, look for the G10 for a better value (at respective msrp at least). You lose an hdmi slot, or something, and/or ethernet. IOW, stuff you probably don't care about.
The 850 will probably have better color accuracy OTB, but I think their previous flagship still gives up blacks, contrast, gradations to even this year's mid-line (G series).
I have a very hard time thinking of a superior TV than the g10/g15 at 46". It might be the very best available flat panel in the world at the given size . . . ?