Should you use punctuation characters (!) in you title tag? <title>URL Shortening at its best! Turn a long url into a short one!</title>
Personally I would avoid this. Sure the search engines should be smart enough to ignore punctuation, but is it worth the risk? In this case non-essentials words precede the exclamation points. So it probably wouldn't really matter if the exclamation points are included or not. I think it would be more crucial if it were right after a main keyword.
title is very important for visiters. your title should draw attention to your site. think that you saw a title like this: "is this the best title format for sites?". what will you do? click or not? i will click.
It depends on the page and the audience. Most of the time, I tend to avoid punctuation, instead preferring an editorial approach to my page titles. Of course, this does not always work in all situations.
It's best to have a title that people would be drawn to by clicking on your link in Google search. Try a few different ways and see the results.