The best configuration for Webmasters...
 

Which configuration of computers are the best of for one webmaster?
What is most important component?

Depends on what your tasks entail... and how much cash you have.

I personally run one mac with two 30" monitors and one PC with two 30" monitors as well as a mac laptop. I run synergy to give me single mouse and single keyboard access across all machines. I also run a linux machine separate that I use for local development and cross browser testing. I use a Buffalo TeraStation Pro (6TB Raid 5) for content storage and backups...

I'm a developer, designer, and (I suppose) "webmaster".

I have a big desk :P