I like many standard tropes (e.g. rescue the princess) if they are player initiated via backgrounds and/or goals.
One that I have seen among some pre-3e groups and seems more common in modern D&D among players, third party designers, and even WOTC designers is the modelling of classes/sub-classes or character concepts upon Marvel and DC superheroes (e.g. Avengers, Psylocke, Batman, Wolverine). There are many superhero rpgs that do comic book superheroes and they do so better than D&D (and I would more more than gladly run/play a superhero game).