A good title can mean anything depending on your site topic.
I'd say these are important for good title tags:
1. The title tag should be easy to read and designed to bring in traffic
2. Place your main keyword phrase toward the beginning of the tag
3. Titles should be five to ten words long, 70 to 80 characters
4. Make different title tags for each page of your site, do not repeat the same Title on all pages
Use the keyword that you want to rank for. In my experience if I would want to rank for a keyword, I would just create a title tag that targets that keyword only, instead of adding additional information to it which actually divides the attention of the search engine bots.
Ex: If I am targeting - "SEO Forum Online" first of all I will optimize the webpage content that should be having enough of that keyword and then make a title: "SEO Forum Online - discussion board" This gives enough weightage for my keyword to rank well.
I have seen people ranking well using spam methods on Title tags.. but that doesnt stay for long.
Keywrod Density is also very important factor while creating a Title for that webpage.
I would definitely go with unique, descriptive titles for each page ... but don't keyword stuff them to the point of it being phony.
Candy, what language is your website coded in? Are you using a server-side language such as PHP or just using regular ole server side includes? If it's just SSI, you'll have to manually type out the description within each of your individual pages. If you're using a server side language, you could store all of the descriptions in the database or something like that.