Close to You (History 4) was by far my favorite HIStory season and is definitely in my top 15 BL list.
It took me a while to warm up to Xiao Li Cheng, at first I found him to be irritating, but by episode 8 I couldn't deny that he was by far my favorite character. I found the interaction between him and Teng Mu Ren to be tremendously more interesting than the interaction between Ye Xing Si and Fu Yong Jie. In fact, I found Fu Yong Jie to be a rather distasteful character and couldn't quite stomach his scenes.
Regardless, I binged watched the season for two nights in a row and the amount of laughter I had to stifle in so as to not disturb anyone had me sounding like a wounded animal. Would definitely recommend.