Jay and Mike recommend "Squidder" and "Saga," and then talk about the weird adventures of Superman's pal in 2011's "Jimmy Olsen" one-shot. Plus, in "Who Am I," Mike has a surprisingly challenging time figuring out the answer, considering how much he enjoys the character in question...
Jimmy Olsen One-Shot (Jimmy Olsen's Big Week), written by Nick Spencer, drawn by RB Silva & Amilcar Pinna.
This story originally ran as a back-up series, beginning in "Action Comics" #890, which featured Lex Luthor as the main character for about 10 issues.
Game: "Who Am I?"
So Jimmy was totally a Giant Turtle:
He was definitely the best Co-Superman:
Also, Superman used to be kind of a dick: