Scanned this from the new brochure I picked up at the local dealer. There are three trim levels in Europe that are designed to suit the needs of different buyers.
Classic: the lowest trim level. The exterior lacks chrome-imitating plastic and they usually come with boring steel rims. The interior makes use of a cheaper-appearing wood (still real though) and lacks many of the features found in the Elegance and Avantgarde models. Basically, a stripped E-Class. Police and taxi fleets are the main customers, but also businesses and some private consumers. The biggest engine you can buy with a Classic trim level is the E320 CDI and E350.
Elegance: the most common E-Class trim level style. It comes with more features and a classier exterior than the Classic models. Not much to say about them other than that they're biased towards comfort unlike the Avantgarde models, which place more emphasis on sport but are still biased towards luxury.
Avantgarde: this is the top and sportiest trim level available in the E-Class. The car is lowered, has a sportier suspension setup and a more direct steering feel than the Classic and Elegance models.