Which is better nokia lumia 800 or n9?

I researched a bit about the two phones and I am still somewhat confused on what phone to pick. I am an app person which means i love downloading different apps but i don't know which phone would suit me. I love the features of n9 but they say it's a dead end, lumia 800 on the other hand has some awesome features too but i don't like the style of it and its inability to multitask. Help? Any advantages or disadvantages for the two phones?

I'm a teenager so I don't know which phone will be of much use for me.
Please, i cannot decide this on my own.