It has nothing to do with the smartness of the TV but the design compromises made in the LCD panels that are used. Some are optimized for limited viewing angles some are not. This also applies to "LED" TVs which are LCD panels lit with leds instead of lamps. As ssddx says go and take a look.
3D TV using VA (Vertical Alignment) panels do face the issue of narrowed viewing angle and considerable color-shifts. The IPS (In plane Switching) panel 3D TV’s hold the upper hand in this case as they give you a wide viewing angle and negligible color-shift.
There isn't any difference in 2D vs 3D either. As AA said, it has everything to do with the panel used. The cheaper the panel, the worse your viewing angle gets. I also agree with SSDD, go look at your local store. Your eye will easily pick out cheap panels when viewed at an angle.