Before an Acer Aspire One with no HD. Gave it away to my sister after a month.

Now a Lenovo S10 Ideapad. Chose it over the MSI, Acer, Asus, etc. Rock solid. Not flimsy or trivial in build.

I would not use a Netbook for heavy duty work. Just simple office (word, excel, powerpoint, visio, project) and browsing. So I keep two portables, an S10 and a Y430 from Lenovo.

Of course Freemind, Firefox and a Netbook makes a very useful portable PC.