I second lil miss cheeky's vote for MAC Flutterby lipstick (from the Madame B collection). My standby nude lip pencil is MAC's Subculture. Another "universal" liner (although it's much darker than nude) is Chanel's Nude lip pencil which is a brownish pink. Stila's Praline lipglaze is my favourite nude lip gloss
If you dont want the heaviness of a full lipstick but want the lightweight feel of a gloss try Vincent Longo lipstains. It comes in a tube like a lipstick but goes on super sheer with a light shine. Lots of moisture and it got rave reviews on makeup alley.