I love songs with lyics that make connections--it may be connections between the past and the present (eg. Mickey Newbury's Heaven Help the Child) or connection through metaphor (eg. Guy Clark's The Cape). Melodically, I don't mind simple provided it's not a total cliche (although much used melodies are OK if the purpose is to focus totally on the lyrics--for example Tom T. Hall at his best). I love it when a songwriter can use a really complex melody/chord progression, yet make it sound melodic and singable (eg. After the Ball by Van Dyke Parks).

Some of my favorite songwriters include John Stewart, Tom Rapp (Pearls Before Swine), Mickey Newbury, David Lynn Jones, Cheryl Wheeler, Joanna Swan (San Ilya), Bruce Springsteen (from his "The River" period), Guy Clark, Tom T. Hall, Van Dyke Parks, Craig Finn (The Hold Steady), and Mark Everett (The Eels).