I'd go curtains, make sure you can tie them at the sides of the window, you'll want them that way most of the time. I dunno if you'd wanna go all the way and get the light slip cloth that goes over the window while the curtains are open to soften the light, but it could make it easier to always have the curtains open. its a tad 'old lady' to go that route.
Im not a HUGE fan of couches against windows unless the sill visible above the top of the couch, its just kinda weird, its like youre trying to prevent zombies from busting in. If I were you, before picking curtains, look at the room and see if there isn't a better way. Plus I assume the window is currently facing the tv, thats horrible for glare and having open curtains even with the old lady slip would cause glare issues and you'd constantly see your reflection while watching darker shows.