It really depends on the specifications of each individual laptop, not the brand. But none-the-less some brands are better than others. Sony and Apple laptops are very nice(but are expensive).
Depends on what kind of laptop you want. Gaming laptops, get an Alienware. There's a couple of good ones for <600 USD. Work laptops are practically a dime a dozen compared to those. Get Sony, Mac, Samsung, maybe even Toshiba.
It runs CPU-intensive games and the like quite well, and if I want to render a video in Sony Vegas, it takes 10 minutes as opposed to 2 hours like it was on my previous VAIO.
If you have a lot of money and want a simple OS, then I'd go with Apple. If you don't have as much money, need a more widely compatible system, and know more about computers, then the rest... well, I don't have time to think up and write them all down so :P
I don't own a laptop, but from ones I have used at school and from my friends, I think HPs run pretty smoothly. Apple is okay, but I've never been much of an Apple fan.
I have a powerful Dell gaming laptop and if something is wrong I get a free repair (for 2 years). Unless they have to replace something and it is my fault,
not macs. nothing works on macs. i'm not even sure if they've made a laptop, but defintely not macs. and i have an HP, it works absolutely fine. even better with this random extra monitor my dad attached.