Best 15" laptop for the buck

Hi Vergers, my girlfriend is going to buy a new laptop, her budget is 600-750 Euros (we are located in Germany), she won't spend more than that, what do you people would suggest as the best option for her.

She will use it more or less as a desktop replacement at home, and will be taking it with her every now and then like 6 times a month to work, or to her parents, so it would be a good idea for it to be someway portable/light, it has to have a display larger than 13 inches, 15" idealy, it would be cool if it had some good battery life, the longer the battery lasts the better, maybe a dedicated gpu, a sdd with at least 256 Gb and it wouldn't hurt also if audio output didn't suck.

She won't get a macbook, no matter if the price is good, she just doesn't want apple, and probably for the money she wants to spend one won't be an option. Lenovo is high on her ranks, preferably thinkpads, then maybe samsung, sony, asus and dell, if you know of anything really good from other brand, please let us know.