In order:

1. Reliability-I am a sixteen year old. I don't want to be stranded all over the place. Simple enough
2. Economy- I wanted a car that didn't eat tons of fuel. Paying for a car that gets 20MPG sucks. And most cars that get 30+ MPG and are in the same price bracket are much less safe.
3. Cache- I wanted a cool car. Something different. Lets just say my other choices were a 1986 Toyota Van and a Peugeot 505 Turbodiesel Station Wagon (SW8 please) Well it seemed the 240D was cheaper (free) more reliable, and cheaper to run than the other two choices, as well as being safer. I still like those Toyota Vans though.....as well as the Peugeots. I think my choice of the MB was best of the three. My mom uses the 240D as a side car...the Honda Accord V6 has been dorment since August. She admitted she wouldnt be using the Toyota Van as a side car...
4. Prestige- It is cool to own a Benz. Its more fun, you feel different while driving it. I myself think I am Helmut Kohl or someone like that. Its just more fun.