[LeonardoA]

You might say that html, body, or head are most important as maybe search engines are not so forgiving of seriously faulty markup.

This poll is more for keywords - which tag is most important for keyword optimization?

[PhilG]

I voted H1 because they are sometimes overlooked when creating a web page. Titles are pretty standard and everybody has them :-)

[T2DMan]

The best answer to the question is that everything is important. If three simple steps of search phrase selection, header tags, and content are not done properly, then a page takes an awful lot of links to get it anywhere.

If the sites navigation, sitemaps, PR distribution is bad, along with a long list of other items that can be done wrong on a website, the site is also a potential dead duck.

Get it all right, and you have a good chance of ranking well.