Whatever you do, do NOT get anything with Windows 8 on it. I got a beautiful Acer Aspire M which has a great screen, backlit keys, decent CPU, less than 5 pounds, 15" screen, ultra-thin, you name it. The pain of getting Linux to run on it, I can't even begin to tell you.
Worst part is, I like it so much that I would buy one again (if I could get Windows 7) without hesitation.