I personally find information on champions to be the most interesting pieces of lore. I really enjoyed the artical about Gangplank and Miss Fortune (probably because I'm a sucker for pirates) in the JoJ because I looked more into what the champions do outside the feild of justice and gives them a bit more depth.
Also relationships between champions be it love, rivalries or simply relating to a common intrest.
I seriously want to more about my favorite champions, especially the more enigmatic ones or the ones who shy away from the spotlight really. *cough* Master Yi *cough*