You should have a different title for each page, but as a previous answer noted, you can have a consistent naming convention and include your website name in all of the page titles.
If you use google webmaster tools, then the content analysis section will report problems if multiple pages have exactly the same title.
The title of your page *IS* one of the most important factors of optimizing your website!
Code:
<title>Home Page</title>
will get you NOWHERE!!
Code:
<title>Web Design Forum - A place to talk about web design and more</title>
This will let search engines know more about what your site is about and will bring more traffic. PERIOD!
Check this out- go to Google, type this in your search...
' Untitled Document ' (without the quotes of course)
Pretty impressive isn't it? ...Sadly enough, there are lots of developers who never put the title of their document using Dreamweaver but look what Google has spit out. Crazy stuff I tells ya!
Title is the most important entity of a website as it describes your web page. Also, it is the most important part while doing SEO. Search engine rankings are majorly dependent on Title tag.
It's also a good idea to combine both competitive and less competitive keywords in your title tag. That way, you'll get a better chance of getting high ranking.