I did some hard time as an it consultant a few years ago, and worked on a lot of sites using different brands of laptop.
It seemed that every manufacturer makes some good and some bad product lines.
Now this isn't in anyway intended to reduce the value of tikrjee's posting, (I suspect his experience was gained a few years later than mine, so there isn't really an argument IMHO) but I have to testify that my experience was that dell laptops were significantly more durable and reliable than toshiba laptops. In particular I highly rated the c series laptops because they are so common, so when I did get a rare failure, the parts were much easier to find and cheaper.
In my opinion the MODEL of laptop you buy is probably more important than the manufacturer.
Certainly, I have seen both toshiba and dell make particular laptop models that had obvious failings, alledgedly some "d6xx" series dells are a bit prone to motherboard failures, yet others with one digit changed in the model number are free of that problem.
If you are buying new, it's all a bit of a gamble, but if you are going for used, then ask a few experts what used to be the best laptop money can buy, then buy the model that more than one of them recomends... :c)
Hope that's useful, it seems to have worked well for me.