Yes You are definitely right dude but he is asking for the most important criteria... So I think it is Performance for me always..
All + warranty. I had three laptops, and all them started going bad within the first year. One was an Altec, the other a Compaq, and the one I have now an Alienware. They all suffered from the loose adapter problem. It caused the Altec to smoke, the Compaq couldn't charge, and now the Alienware goes out sometimes even though it claims there is a full battery. I tried to use the warranty for the Compaq, but didn't receive any help. So I had to find a shop that could repair laptops(those type of shops are pretty hard to find). Found one, got it fixed. A couple of years later it started giving me the same problems. During that time I moved to another state and had to search for a place to repair laptops. Found a place, but after a week they said they didn't want to repair the Compaq and the Altec because of the risk of fire. Found another place, but it looked shady. You know one of those places that may be there one day, but the next it won't be. So for a couple of months I refused to go there. My mom kept nagging me that we should go there. I finally gave in, and for months they claim that they were in the process of fixing it and before I moved they claimed they lost them. That sucked. Wish I would of sold the laptops to them instead, but my mom didn't want want any of that, even though I insisted we do it since it's so hard to get them repaired. If I ever by a laptop again I will have to look at the reviews for the warranty service and get a 3+ year plan.
Of course everyone would choose performance first then maybe followed by other criteria like brand, size, etc... So I voted for performance...
They are all something I'd take into consideration, but design would be my biggest. It would be better having a sleek slow comp (upgradable) than a thick unattractive one (better off getting a cheaper desktop).
Too bad theres no Battery Life option. To me if a laptop runs for less than 3 hours its not really worth the effort. I choose Performance because if it can't run your programs its useless!
Everyone's made good points so far. Battery life like Riot said is a huge thing to take into consideration, especially if it's being used on a trip.
Since laptops arent for games and hard processing i chose design but considerer also size. It´s what you need for traveling and working around everywhere (okey design is just fashion)
The most important for me is it's performance although the laptop's size consideration comes a close second.