Visit - Someone comes to your web site and looks around a bit. They may go to one page, or they may go to 100 pages, but they're still only visiting once. 

View - How many pages were seen during a visit.

Hit - How many physical resources were requested from the server by that visit. Pages are made up of many items (images, text, etc). Each of those is a hit, while a view is the page itself

Think of it like a book store. A person goes into the store (visit) and picks up 5 books to buy (views). While he is holding the books, he flips through them and looks at a few pictures (hits). So he would have 1 visit to the store, 5 books handled during his visit (views), and maybe 30 pictures he looked at (hits).

So which value is more useful?  It depends on the use of the information.  If you're in marketing and you're striving for bragging rights or high activity numbers, use Hits.  However, if you are using your stats to actually identify trends and the personal impact of your site, use Views and Visits.  Hits can always be inflated artifically, by adding a few more images to a page, for example.  Visits and Views, however, represent people coming to your site and the number of web pages they saw, which is much more useful for analyzing usage patterns.