I assume you mean a 'netbook'?
I don't know that you can go too wrong with any of the major players in the field:
Acer
Asus
Lenovo
There are probably one or 2 others in the mix. I'd check out a site such as dealnews.com and just look through their netbook section, read some of the posts about the ones you are interested in so you can get an idea on price trends and what a good price is.