I don't know how many times I get asked this question - see title. Jeremy from GPANSWERS has this great article that I can now just send to people to read and I don't even have to do any work. Cool!
It is funny though, and please read the whole article, that in the end he is in the process of buying a Lenovo Thinkpad which is what I have used now since the 1990's - why do I use a Thinkpad? Warranty, Warranty, Warranty, and the ability to fix them (I mean broken parts), myself also ..... they have always traditionally made Thinkpads to be field fixable.
Jeremy covers all the questions including, Netbooks and tablets and OS and hardware. So read it, book mark it, and SPAM it to all your friends and family this season instead of answering all those stupid questions - unless you like doing that sort of thing - I don't, I really don't want people to really know what I know anyway :)
Jeremy's Guide to how to buy a laptop for normal users