There are various easter eggs hidden in Infamous 2.
Red Ring: Most humorously, you can find a Red Ring of Death store in New Marais - which sports a faithful rendition of the Xbox 360's hardware issue in it's logo.
Theater Parodies: When passing the New Marais theater, look for the film titles that parody other video games:
Assassin's Need (Assassin's Creed)
Call of Booty (Call of Duty)
Epic Hickey (Epic Mickey)
Hey, Low Reach (Halo Reach)
Latch It and Skank (Ratchet and Clank)
Little Big Unit (LittleBigPlanet)
No Ned for Speed (Need for Speed)
SLY (Sly Cooper)
Solid Serpent The Man (Metal Gear Solid/Solid Snake)
Uncharted Love (Uncharted series)
Added by: MongooseGeneral Jun 22nd 2011, ID#3962