In the comics, Superman can come off as a bit of a boy scout, a little flat and unrelentingly - unappealingly - good. But in the hands of a good writer, this character takes on more nuance.
For instance, I just read a really funny story by Nathan Pensky called "Lois Lane’s New Boyfriend Rubs It In After Beating Superman At Ping Pong At a Family Barbecue." It's title really says it all. Then there is "Man not Superman," a story by Jonathan Goldstien. Also told from the point of view of Lois's new, human boyfriend, it explores the dichotomy between Superman's hero persona and his alter ego Clark Kent.
My absolute favorite literary retelling of the Superman story has to be "It's Superman," by Tom De Haven. The book is set in the 1920s and 30s and explores Clark Kent's early life as he navigates family, friends, growing up and his place in society. It reimagines him as plodding farmboy of average intelligence and a deep ambivalence about his powers. For the first time, readers start to understand the man behind the cape - reminding us why his story appeals to us over and over again.