Usability, accessibility, compatibility (and standards) are the key elements of web design and should be planned before anything else, not just tagged in as an afterthought.

Aside from offering developers the chance to include a level of interactivity that goes beyond print, those elements are what separate print design from web design; compatibility being the most important (what good is your site if it's held together with ie6 hacks, or it only renders properly in safari?). Once you get the key elements down, you can work on typography, layout, speed, colour etc.

That's a very nice point Pete, I can't really disagree with that.

One thing I must add is: are the elements you just mentioned (Usability, accessibility, compatibility (and standards)} are things you look at when you first visit a site, or is it the typography, the layout, the speed and so on? I mean, first impressions take a huge roll in web design, because they are the "key" for people to keep staying in the site.

I think we can divide these elements into two different types: The inside "look" of the site (which covers elements such as usability, accessibility, etc.) and the outside "look" of the site (which covers typography, colors, layout, speed and so on)

So that's what I am really wondering, what 3 elements (if even there are only 3) do you need to pay the most attention in order to build a site to it's top?