As in the writing and not so much the acting. (but sure if the acting made it worse)
I have to say it's one god awful line from Far Cry 3's lovely protagonist Jason. "His name is Buck and he likes to f..." *in a slight southern accent*. Oh my fucking christ. Doesn't help that the game plays it every time you load back to that checkpoint. I facepalm and give a deep sigh every fucking time. Line's so fucking horrible I want to run Jason into a flaming weed field. FUCK.
oh ya, what's your pick? Any line so bad it stuck with you for a long time?