If you're in the market for a netbook—the gimpy kittens of the laptop jungle—know this first: on the inside, they're all basically the same. Making the little differences all the more important! And yes, they do add up.
For our Battlemodo, we decided to look only at netbooks powered by Intel's Pine Trail (Atom N450) processor. Netbooks sporting older processors are a bit cheaper, but they're also a little slower and don't achieve the same impressive battery life as Pine Trail. And they've been reviewed to death elsewhere.
Netbooks with an Ion GPU are also available, but they've got their own baggage. First: they're around $50 more expensive than non-Ion models. Second: they're not available yet on Pine Trail. So you can either settle for an older processor with Ion and take a battery life and performance hit, or wait until the first Pine Trail-compatible netbook—the Acer Aspire One 532G—comes out later this year and pay the premium. Once you're spending $500+ on a netbook, though, you may as well step up to a full-function ultraportable.