My favorite episodes are always ofcourse the ones where the whole club goes to the cons it just makes me think of when i go to anime conventions how crazy it gets but how excited everyone is and omg the shopping O_O and all the wonderful cosplayers ^_^
So far that I can recall, season 1 when the club is trying to explain doujinshi to Saki Kasukabe. That was full of laughs and very informational. Though, my current club just started watching season 2.