Gwen's crush on Merlin vanished after 1x09 actually! It was present all over the place in that episode, and then she had her huge realization about Merlin's main priority being Arthur, and then in the next episode she and Arthur started having Meaningful Moments. Also also generally what I want is OT4 (and Lancelot can join in if he wants!) AWESOMENESS. Because they are all SO AWESOME.