I have a Dell XPS15, running Linux Mint (never even booted the stock Windows OS) and have had nothing but good things to say thus far. It's light, it runs quickly (playing a good bit of Kerbal Space Program with my daughter) and it was relatively cheap (I got mine for $1100 last year). I'd recommend it to absolutely anyone.
Newegg link: http://www.newegg.com/Product/Product.aspx?Item=N82E16834300...