Looking for laptop for girlfriend, new or second hand... advice needed.

So I build my own PCs, but I never really had much dealings with laptops. The two I've owned lasted about a year each. There are so many options I don't know where to begin.

Ive always liked asus but I'm not sure what other brands to trust. Of course no hp or dell ha.

I'm looking to spend around 500 at most. No windows 8. Probably going to run pure ubuntu or dual boot with windows. She has a pc I built her for heavy lifting so it doesn't have to be crazy, but I dont want it to lag if she has 20 windows of chrome open. Also something that runs cool/is durable. She's bad about leaving it on the bed and while she doesn't need a machine coated in rubber, a more hardy machine would be nice. Battery life isn't too important. Probably just going to use it for Internet stuff, word processing and ebay stuff.

Thanks guys. I'm so lost when it comes to laptops. So many options.

Refurbished thinkpad?

That'd work fine. Honestly, I've had just as many problems with high end Lenovo, Toshiba and even Asus and MSI laptops as I have with HP, Gateway and Dell. Actually, out of all of those, Gateway has the best track record out of the systems I've worked with.

If all she needs is a durable web surfer, I'd go with this

Many laptops have intake vents in the bottom which can (will?) lead to overheating if placed on the bed or carpeting. Take that into consideration as well.