I'm thinking about buying a new laptop, and while I bought my original one oblivious to the fact that there could be different quality screens out there, after seeing the screen on my sister's netbook I realized that I might have to be cautious with my next purchase.

Granted, I did not confirm that the reason my sister's screen looks the way it does is due to the screen itself and not color scheme/graphics card, but I know very little about the different screen technologies and how they differ in image quality and therefore can't really tell if wondering about it even makes sense or not.

So what I'm asking is: should I be worried about screen quality? And if so, what technologies should I be looking for? How do they differ and which are the best ones? What are the different elements that determine the quality of a screen and which stats should I go for in each element?

For the record, I'm not interested in opinions about screen size, but picture quality for lots of reading/coding.