Personally i prefer Asus, if i had to choose another brand if ASUS wasn't available would be Lenovo then Dell and finally HP. ASUS's laptop have really good design and venting systems which keeps the laptops quite cool even without a cooler, so my vote goes with ASUS.
- Asus.
- Lenovo.
- Dell.
- HP.
I don't really recommend VAIO, they tend to be to delicate, replacement parts tend to be quite expensive. (Ya i am looking at you, trackpad!).
Personally used the following brand for at-least a year (Dell, HP, Sony, ASUS, Lenovo, Toshiba and Acer).
Currently using an ASUS Ultrabook.
Edit 1: Toshiba is also quite good, but they are a bit expensive at my place.