If I am watching TV while sitting on the sofa, and someone were to ask me "Where is the TV," I would answer "The TV is in front of the sofa" if I were to choose from the two examples you provided. However, the phrase in and of itself sounds a bit awkward. I would actually say "The TV is over there" if I someone asked me where the TV is while I'm watching it. Hope this helps!

Thank you everybody, but I'm a bit confused.Do you think there can be different prepositions for Br. English and Am. English? :)

You would say 'opposite' here, because it as though you and the TV are facing each other, with the space of a few metres of living room floor between you. You wouldn't say that the TV is in front of the sofa. This would suggest that it was directly in front of the sofa - too close to watch, and probably facing in the wrong direction, too. You might have a small table in front of the sofa, for example.

Probably "opposite of." To me, "in front of" kind of implies more proximity than I'm sure you mean. But the most common way I'd expect this to be expressed would be "The TV is across from the sofa."