I've been making my way through my husband's collection(he's still a kid at heart).

I really liked Emperor Joker (Mxy gives his powers to the Joker). Also, Identity Crisis was very good (a bit more of a Justice League story, it got really goods reviews)

I didn't care for Birthright, they tried to re-vamp Superman's origins again (I didn't like how Lois was written). DC doesn't really seem to be sticking with though, so I would recomend more the 86 re-vamp Man of Steel mini-series. Oh, and the World of Metropolis, World of Smallville, & World of Kyrpton, each 4 part mini-series which came out after the Man of Steel re-vamp. They each tell different stories about Lana, the Kents, Lois, Perry & others.