Don't go with HP if you want any support what so ever for your laptop. Two of my room mates, Kris and Sarah both have HP laptops and support horror stories to go with it.
Kris sent his laptop in for repair since the wireless card was not working, and his internal network failed to work. He sent it in, and was told it would take about 2 weeks to repair. After two weeks and still no word he called HP asking where his laptop was, he was told it was being repaired and it would be another week or so and it would be on its way back to him. A month since sending it in has passed and this time he calls up, pissed off that they are giving him the run around. They say they will look into it and give him a call back in the next 48 hours. Does not happen, so he calls up again and they say they will ship out a new laptop to him. He reminds them he also needs the extended battery (more cells, longer battery life) which he was told to ship with his old laptop. Finally after another two weeks HP ships him a package. It seems awfully small for a laptop. They shipped him the battery. Still no laptop. He finally calls again, and this time they will make sure a new laptop is shipped out to him. Sure enough, after two months of the original ship date, there is a new laptop. This time instead of having an ATI graphics card, it has been downgraded to an Intel GMA card that eats up part of the RAM installed in the laptop, and has had the CPU changed from an AMD to an Intel. He decided to keep it instead of trying to get it replaced with what he had before, since the Intel CPU is a bit faster, but the graphics card still sucks.
Sarah had a similar story, except it only took HP about a month. The power jack on her laptop was broken, and whenever she would power it on to charge the battery, she would have to hold it in a specific location, otherwise it would not charge. Classic case of a loose power plug that needed to be re-soldered. So she wipes the machine (so the drive is blank) and sends it in, with a note specifying what is wrong. A week later it comes back. Power plug has not been fixed, but Windows XP has been re-installed, and the tech put a comment on there that everything seems fine. Clearly not the case, since the power plug is still broken. So she sends it in again, and this time it takes them about 3 weeks. It has finally come back, and it has been fixed, but it has not been without her getting on the phone and yelling at managers and complaining to them that it is absolutely retarded that a laptop comes back without the issue fixed. She even bought the extended warranty from HP.
I have another room mate, Mark, who has a Dell laptop. He has the O-**** warranty and has the service to have the tech come to our house to replace the hardware in his laptop. He has had over 30 support cases to have stuff fixed on his laptop so far. Hinges that have broken, DVD-rom drive that has broken, internal network failed to be found, wireless card broken, RAM that needed to be replaced, keyboard and many more. Battery that has stopped charging. And this laptop is practically babied. It does not get thrown around, and does not get abused. Dell has always been very fast, once he gets through to them that he is unable to run most of their diagnostic tools because he is in Linux (they want him to go to an ActiveX website so that they can do remote help stuff :/), and most techs don't understand the word Linux. Their turn around time is pretty damn good though. When he calls up, the tech is normally at our house within the next day or so to work on it. So when you do have problems, Dell seems to be a good bet, if you are willing to pay extra for the service.
Apple, I have had my own problem with their hardware. You may read my story on my blog at
http://personal.x-istence.com/node/131 . I eventually after going into Apple with different problems over a four week period able to get them to replace my MacBook Pro with an entirely new one, free upgrade included. My support issues have always been handled professionally, with care and quickly. The genius bar is absolutely awesome. The guys there know me, so I rarely have to sit and explain to them what I have done and what I have not done, which makes it so much easier for me to just walk in and get that what I need fixed. While they don't always have the parts required in-stock, their turn around time is normally two to three days, and then the swap is completed while you wait, or within a day. Appointments are made online, and are really easy.
Toshiba has always been very quick with their hardware support. I have a very old laptop that was not supported under any warranty and they still sent out the parts I needed to get it back up and running, free of charge. I have not had any experience with them outside of this. Your milage may vary.
ThinkPads from Lenovo are a good bet as well. When Lenovo bought out the IBM computer business they also bought all the support with it. A friend of mine, David, had his ThinkPad fall out of his backpack at the top of the stairs. It bounced all the way down, where it fell apart into pieces. He called up Lenovo and they sent out a box. He put all the parts in it. A week later he has a box show up, it is a brand new laptop (same one he had) with his hard drive in it.
Gateway, my room mate Victor owns a Gateway laptop which he bought from my school in their computer sale. At one point he had it balancing on top of the railing for the stairs. My room mate Mark knocked it off, and the laptop went bouncing down our stairs. Screen was broken, battery was lying a few feet from where it landed, everything about it was broken. Luckily it was still under warranty from the school, so he sent it in to gateway. They replaced the parts of the case that were broken, and put it back together. Took about a week. No charge or anything. Best $100 he ever spent on a laptop!
Well, there you go, there are the experiences with different brands that I am aware of, and or have experienced myself. They have all been laptops, then again I am a computer science major and I want something I can easily take with me. Being without a laptop is almost like being naked. It is easy to feel lost