I speak from experience - skip Toshiba. I know thats not on your list, but I have had nothing but problems with mine. Then again, I'm not a casual computer user, I use(d) my laptop for everything. While under warranty, the mobo died. Just out of warranty the harddrive died. After that, I have had two power supplies go on it. Its been sitting in the corner for the past two months while I catch up on my bills to buy a new one.
I work in a computer repair department at MSU in the College of Engineering, and all of the toshiba's that come in have had catastrophic failures. We reccomend Dells, and if you go dell, get their warranty (get the extended warranty on ANY laptop you purchase). Dell is really good about their warranty, and 9 times out of 10, they'll either overnight the part you need to fix it, or they'll have a tech out the next day to repair the problem.
We've had very few gateways come in, but IBM is along the same line as dell with their warranty work.