I have been through several laptops; 1 Toshiba (broke it), 3 compaqs (broke all 3), 1 Dell (still running), 2 IBM (1 got stolen, the other is still running).
here is my vedict:
Toshiba - Generally ugly and heavy, for sexy and light you are paying too much money with this brand.
Compaqs- Offers alot of variety but nothing in particular stands out.
Dell- Excellent Specs, bad build quality, Dell has a history of poor customer service and issues with power (battery, adapters, power ICs). The battery on the Dell D600 died a few months after purchase and so did my sisters battery on her Dell. My AC adapter stopped working a few months ago and I had to buy a new one). The ventilation design on my D600 is retarded as it overheats unless I prop a book underneath it.
IBM- Used to be expensive, but now they are very affordable. The best build quality of any laptop brand. Light, fast, reliable and has alot of nice touches. IBM is like buying BMW, it has nifty stuff and they pay alot of attention to detail. Price wise I think they are maybe 200 bucks more than competing brands with the same specs on paper. I saw an IBM t43 from the IBM.ca website for 1350, which is an awsome deal. Thier business class (T Series) which is their mainstream model would qualify as "thin and light" with other brands. Also IBM's battery life is in general superior to all other brands.
I imagine that if I took all my laptops that I ever owned when they were new and dropped them from about 5ft the only laptop to come out still working would be my current IBM T40.
I still have my Dell D600, I use it for games and surfing since it has a decent video card and the screen is very bright. For travel and serious work I use my IBM T40.