Definitely Dylan. While Cun Xi does end up liking Xin Yi and gives her confidence, he can act like a total asshole to her and he did some pretty stupid things to her (abortion aside since he as in a tight spot).
Dylan on the other hand, was always nice to her, and even helped her relationship with Cun Xi regardless of his feelings. That and Cun Xi needs to decide between Anna and Xin Yi (that drives me insane, you obviously love one, ditch the other already)!
I can see the sun setting, it’s casting shadows on the sea
Dylan is a very manly and serious character and I liked him more, before they went to Shanghai and he changed his look, don't like his "pony tale" now, but I would go with him even with that!
Well and Cun Xi became more "interesting" even by his look, well he does became more serious and mature for 2 years and he is in love with Xin Yi, he always was, but he was blind from Anna's brightens.
I would want Cun Xi for Xin Yi, cuz I want Dylan for myself!!