Many have said it already, but let me just add my voice: ClearType technology is the most wonderful thing to hit Windows in a long time. I recently received a new computer at work (3.4Ghz hyperthreaded, 1 GB RAM, 80/200 GB disks–a screaming machine, at least compared to what I used to have). and during the setup process (3 versions of Visual Studio, Office, dozens of developer tools) I remembered that I needed to turn ClearType on.
Wow. It’s like the same difference when you’ve been needing glasses for a while and finally get them and realize that the world isn’t that blurry after all.*
It doubles the perceived resolution of LCDs.
(* only a little ironic that ClearType works by deliberately “blurring” edges through antialiasing.)