Need serious advice on laptop upgrade?

Up until now I have been in the computer stone age. I have a Dell desk top computer at home for about 4 years and it was refurbished when I bought it. The computer itself (not the screen) is huge and I want to upgrade to something small and sleek. I want it to be portable, super fast and have a good amount of memory. Battery life should be good but I don’t really expect to use it too far from an electrical outlet so thats not important. I wont be gaming. It’s primary purpose will be internet surfing, downloading and watching movies and music (I’m a music and movie fiend), scanning, downloading, uploading, storing pictures, writing documents, chatting online and some school work and research. I don’t need the absolute best of the best and I don’t want to spend a fortune. My limit is $800. When I go into Best Buy or Staples they either try to sell me everything but the kitchen sink or they know nothing about the products. I have gone online to read reviews about different laptops like Dell, Apple, Lenovo, HP and Sony just to name a few but the reviews all seem rehearsed. Can anyone here give me an opinion based on my needs? I want a laptop that will last a while and not give me a list of problems (at least not right out the box). Sturdy, good reputation, few if any issues and gliches and upgradable if necessary. Simple.