It's free, most of the programs that run on it are as good or close to as good as the equivalent programs on Windows or OS X only free, it's fast (very fast indeed), viral attacks and malware problems are practically non-existent, it's progressively updated and maintained by people who test each new innovation rigorously, no more defragging, if you have a virus scanner program like Clam you can use a Linux laptop as a safe conduit for sweeping the filth out of a non-Linux machine.
I've known people who use their laptops as just basic web surfing machines, playing music, storing photos etc who were about to throw out perfectly good laptops because of clogged up Windows accounts who when the switched over to Ubuntu got essentially a new faster than ever laptop for free.
As I said earlier you don't have to install it to try it, you don't have to install it exclusively if you chose to go there and you don't have to give up your Windows favorites.
A new laptop would go like a rocket on Linux and Ubuntu can be made to look and feel exactly like any operating system you fancy if you are worried about the aesthetics of the system.