Apple MacBook Pro 13-inch (Retina Display). It's not leather, but shouldn't it be? My current computer got me through my undergraduate work, but I don't think it's got the gusto to get me through my graduate work. If, and only if, you have a spare MacBook lying around, perhaps you could show me how well it fits in the bag!
As i´m super satisfied with my new laptop, I recommend it to everyone and I´m happy everytime I start it. I´m happy that i didn´t just buy a notebook to have one so i definitely made the right choice in doing throughout research and really taking time to decide on the model.