I personally like a physical book over a digital one, however if anyone is into digital graphic novels, Amazon has a ton of Marvel ones on sale right now, like for instance the Old Man Logan is 90% off on the front page here
https://www.amazon.com/s/ref=sr_pg_1?fst=as%3Aoff&rh=n%3A133140011%2Cn%3A%21133141011%2Cn%3A154606011%2Cn%3A156104011%2Cp_n_feature_nine_browse-bin%3A6771870011&bbn=156104011&ie=UTF8&qid=1496424068&lo=digital-text