Depending on the site I visit I find in some cases the site title as, Big Widget Supplier and on others, BigWidgetSupplier.com and I often see a short promotion - All The Best Widgets In Stock following in the title. Question, which is the best way to go and is there any penalty for switching?
The title tag is used for two main purposes - usability and search engine ranking.
Usability - The text from the title tag is shown to users in several places. It is often but not always used in the search engine results page. A more user friendly tag line with some sales pitch included may help to increase the click through rate. Also your title tag is used when people bookmark your page.
Search Engine Ranking - The title tag is a semi-important part of the search engine ranking algorithm. Including your keyword in the title tag generally delivers a boost to your ranking power. Excessive keyword stuffing & duplication may also deliver a lower ranking.
I generally try to keep my title tags shorter, include the main keyword, possibly including the site name at the end of it to help my branding efforts. This helps to balance the need for usability & search engine ranking.
This really doesn't answer the question. I'm finding many directories want the domain as the title, but not with the .com or the words together. example, domain bigfatwigits.com they want the title as Big Fat Wigits. So I'm wondering if search engines will react badly to the title being BigFatWidgets.com - Big Fat Widgets also google is now asking in webmaster tools whether we want the www or not, which way to go for a new site?