If you're wiring for an outlet, it's pretty much standard to use #12/3 (includes a green ground wire which is grounded at your electrical box). You don't know what might be plugged into the outlet at a later time (you might one day want to add some additional equipment) and #12 is good up to about 20 Amps. On the other hand, #14 is plenty big enough to handle the LED TV you're talking about. You should however, use #14/3 with a ground to meet wiring codes and to provide equipment grounding and protection. A surge protector will be seriously compromised if it doesn't have a ground, and that would be an added recommendation for your new TV (a surge protector, that is).