I've had excellent experience with Dell Latitude laptops. I was using a Dell Latitude E6420 running Linux Mint for about two years until it stopped charging completely and I had to keep it plugged in for it to work. I ended up replacing it with a refurbished E6420 with almost identical specs for a little under $300. It's my primary computer and, with the 9-cell battery, can hold a charge for about 8 hours.